How a Nuclear Lab Helped Catch a Serial Killer
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Hi, I'm Wendy Zuckerman and you're listening to Science Versus. Today on the show, how a lab that designs nuclear weapons helped catch a serial killer.

And if you're going to do true crime, you better bring in the true crime queen, host of Crime Junkie, Ashley Flowers. Welcome to Science Versus. Hello. I'm so excited to be here. So something that a lot of people might not know about you is that you graduated from biomedical science. That was your degree. It was. And we are twinsies. We both have this degree. I thought I really wanted to be a doctor when I was young. And I was...

I think fortunate enough to have to work full time to put myself through school. And I worked at a hospital for all five years and went to school at night. And I got to work side by side with residents who you have to be before you're a doctor. And I was like, oh, that's not the life I want. Right.

I made a bit of a pivot and I finished my degree with actually a focus in research. And so what do you like about science? I like facts. And I think so much in life can be

so subjective. And what I love about science is it feels like there are real answers and not just opinions. Sometimes things get to be black and white, and that's not very often do you get that. Yes. Yes. I think that's one of the reasons I love science too. It's a way to understand the world. If science is your side piece, I guess, your true love is really mysteries that I've heard you say that you

are obsessed with solving mysteries. Obsessed. What is it about a mystery that just grabs you and you cannot let go? I think I'm just an overall like a very curious person, the more that I've like really drilled into it. And I want to, I want the answers to everything. The universe, I want the answers to all the unsolved mysteries, like give them to me. Well, today we have a real mystery for you and it's got a whole bunch of science in it. So should we jump in?

Let's do it. It's two days after Christmas in 1996, and a woman named Salby Esatrian is rushed to Glendale Adventist Medical Center in California. She's 75 years old and is having trouble breathing. One hospital worker told the LA Times about her. He said, she's a sweet old lady. She got treatment at the hospital. And on December 30th, she's breathing on her own. Things are looking pretty good for her.

But then three and a half hours later, Salby was dead. That same day, Eleonora Schlegel goes into Glendale Adventist. She has some chronic illnesses, a nasty case of pneumonia. On New Year's Eve, her son Larry, he said in a documentary that she was sitting upright and breathing as best as she could.

They apparently have this toast and say next year will be better. Oh, no. But on January 2nd, Larry sees a message on his answering machine and it's from the hospital. His mom had died. And they're just toasting the day before? Yeah. Yeah. Oh, my gosh. Similar situation happens again.

Jose Alfaro Sr. He was a father. He'd fought in World War II. He arrives at Glendale with severe pneumonia and two days later is found dead. And at the time, these deaths are sad, of course, but they don't raise any eyebrows because these patients, they were sick, had chronic illnesses. You know, it's a hospital. People die. And how close together are all three of these? Like pretty close? Really close within days of each other. Okay. Okay.

A few months later, though, rumours have been circulating that the deaths of patients like these didn't happen just because they were sick and elderly, but that these people were killed on purpose by someone who works at the hospital. The rumour is that someone is injecting something into their IV.

And Ashley, tell me what your face is doing right now. Well, I'm just... What do you mean rumors? Like, I feel like this isn't something that should be a rumor if people know that someone's walking around, like, killing people. Yeah. We're going to get into what these rumors are.

who everyone is blaming. Okay. What on earth happened here and how the hell a lab that develops nuclear bombs got involved? Naturally. Naturally. Are you in? I'm in. We're going to do this just after the break.

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Welcome back. We've just found out that patients at a hospital in California are dying under perhaps suspicious circumstances. Ashley Flowers, host of Crime Junkie, is here with us. Hey, Ashley. Hello. So it's now 1997. Whispers are going around that one guy might be killing these patients and his name is Efren Saldivar.

So we talked about him with science journalist Sarah Scholes, who wrote a book about nuclear weapons and stumbled across this case. So Sarah told us that back in Vertigo Hills High School, Efren was a bit of an oddball. He worked at a grocery store. He played the oboe. He didn't have a ton of friends, but he was a pretty well-liked kid and was kind of like the leader of the misfits.

In the senior Will's section of his high school yearbook at Vertigo Hills, he wrote, I, Efren, of great mind and hunk body, hereby will three quarters of Vertigo's female population my enduring love and passion. The right to preserve me in their hearts and souls for the rest of their lives and other times.

Eternally yours and mine, Efren Stud at Large. Literally, Efren, no one asked. Like, what? I mean, it's real oddball energy there. Was he actually of hunk body? You know, he was pretty nerdy. A hunk would not be. If I was making a film, a high school film, he would not be cast in the hunk role.

It would more be in sort of the dweeby oddball category. I love it. Okay. So Efren makes it through senior year, but ultimately drops out of high school. So he's working at a grocery store. And one day... His friend came in wearing a medical uniform. He had a friend who was working at a hospital. And he...

He just really liked this guy's uniform. And he was like, I guess I'll do that. I guess I'll get a medical career. I like the clothing. Scrubs? Yeah. Is he talking about scrubs? He liked the scrubs. Which might sound like a weird reason to go into the healthcare profession. But, you know, you're 18. Cute fit. It's as good as any reason. I like cute fit. I like it. It's pajamas. Like, I used to wear scrubs. They're pajamas. Yeah.

I think the person who came in also had a stethoscope, so that might be kind of cool as well. Just like radiating power. Yeah, I get it. So Efren enrolls in a respiratory therapy program, and respiratory therapists help patients who have trouble breathing. So they give patients drugs, oxygen, and manage ventilators, stuff like that. Okay. And so when Efren is just 19 years old...

In 1989, he gets a job at Glendale Adventist Medical Center. I see where this is going. This is the place where the patients at the start of the episode died. So at Glendale Adventist, part of Efren's job was to take care of really sick elderly patients. And Efren is put on the graveyard shift. So he starts moonlighting and working at other jobs too during the day, other hospitals.

So, Everett is working all these jobs. He's a bit overwhelmed. And at one point, he starts gaining some notoriety at the hospital. So, here's Sarah, our journalist again. He had a reputation at work for having a magic syringe. What did they mean by that? Not magic in the positive way, but magic in the deadly way. His patients...

died faster than other people's patients. That's not magic, that's murder, right? Magic feels like a really weird word to describe it. And this is where, from reporting about this hospital at the time, it seemed like the healthcare workers, particularly the respiratory therapists, had...

This really, you could call it a dark sense of humor. They just, they played practical jokes on each other. So having worked at a hospital, having worked with a ton of people in law enforcement, I have seen this in a place where you see a lot of death or there's like a lot of trauma, having that like very dark sense of humor tends to be, I've seen a way that a lot of people deal with it. So it's not even super surprising to me to like see that in the hospital setting. Yeah. But still. Yeah.

And then sort of other things start happening that make it harder to pass off as a joke. So here's Sarah. Someone had seen him putting something in an IV line that they thought shouldn't be there. A co-worker also says he sees an empty syringe and a bunch of drugs in Efren's locker.

drugs like morphine and this medication called succinylcholine, which is going to become important later. And so in April of 1997, a co-worker ends up reporting Efren to a supervisor. But the supervisor doesn't know about the drugs in the locker. So they really don't have that much to go on. It's just kind of rumor-

in a place where there's a lot of rumours and jokes going around, but still they look into the hospital records to see if Efren's patients are dying more often than other patients. Mm.

And... Didn't find anything because his patients weren't actually dying at a higher rate than anyone else's. Oh. Yeah. So they didn't find anything unusual here. They let it go. Efren keeps working. And it's not until almost a year later, in February 1998, that the hospital receives another tip. From someone who says that there is a respiratory therapist who, the quote is, helped a patient die fast...

And is this like a euthanasia situation or what does that, like, what do they mean? The guy on the phone ends up being a pretty dodgy guy with a criminal record and seems to be implying that if he gets an extra $50,000, he'll give more information. Wow. He's basically extorting the hospital. Yeah. And so this time the hospital calls in the Glendale Police Department and

And by the way, we did reach out to the hospital to ask them about parts of this story. And let me guess, they didn't want to talk? Yeah. Let me finish that for you. Thank you. Yes, all questions should be directed at Glendale Police Department.

So enter Detective Sergeant John McKillop from the Glendale Police Department. He is put onto this case and John and his team start poking around. And John told us that he is actually not buying this idea that Efren is a killer. I was a sceptic because it just seemed odd. The whole thing seemed odd. What was so odd about it? Well, I mean, to be honest, you're talking about

someone trying to extort money out of the hospital to give information versus a major serial killer. I just thought it was a bunch of bull, so to speak.

How are you feeling at this point, Ash? What's your spidey senses telling you? I mean, I under... Well, I understand what he's saying. And it's funny, like, I feel like the way that I'm at least hearing this is that the hospital really brings in the police because of the extortion, not because of the threat of somebody actually killing their patients. Yeah, that's John's memory of it as well. Yeah. Yeah, yeah, yeah, yeah, yeah. Gotcha, gotcha, gotcha, John. So...

I understand why he would just kind of come in with that thought of like, well, this can't be true. It's just some guy. He wants $50,000 to out a serial killer. Like, there's no way.

I would probably think the same thing too. Yeah. But still, to sort everything out, on March 11th, 1998, John's partner, Detective William Curry, calls Efren into the station just to ask him some questions. But John actually had something else to do that day. Will was going to bring Efren in to interview him. I'm like, I'm going to go play hockey. So I went to my hockey game. You were so sure that, like, this is silly. Yeah, exactly. Exactly.

I love it. Right. It's like, no need. I've got hockey. You take care of this. But it turns out this was not silly. When the cops start questioning Efren, he confesses to killing dozens of patients. All they had to do was ask some follow-up questions and the dude just folds? Pretty quickly, he says he killed 40 to 50 people. Yeah. Yeah.

Over, like, what span of time? It's pretty vague at this point. It's very, the cops just found it very strange, particularly given this attitude of, I'm going to go play hockey, sure, bring him in. They want him to do a polygraph. The way that the cops remember it is just all of a sudden he starts talking and they were in the room going, oh, someone get a pen, write this down. Exactly, exactly. And so John is playing hockey.

I mean, they literally pulled me off the hockey rink to tell me, hey, your partner's on the phone. There's something going on. You need to go. And when I picked up the phone, Will says, this guy's confessing he's rolling over. You need to get in here right now. You know, now we're talking about murders.

Oh, my God. So not only did he say that he killed patients, but he also told the cops how he did it. Like, sometimes he would kill them with these drugs. He said he either used a drug called Pavalon or one called succinylcholine. Which is what they found in his locker. Wow. Exactly. Does he say why?

At the time, he said that he did it to ease the suffering of these patients. But we had our homegirl over here who's like cheersing to a brand new year. Yes. Yes. It doesn't really make sense. He sort of fashions himself as a little bit of an angel of death type character in that room that he didn't like seeing the patients suffering, says things like that. Okay.

So we wanted to know a little bit more about what these drugs do in the body and why they're used by healthcare workers. So we talked about this with Dr Ian Musgrave, and he's a molecular pharmacologist at the University of Adelaide in Australia. He told us that pavilon and succinylcholine, they interfere with how a particular neurotransmitter works in our body, and ultimately they can paralyse your muscles. They stop the nerve signalling, so your muscles just stop working.

They may be saying, okay, why would you want to paralyse your respiratory muscles? That is, if you don't want to kill someone, why are we using these drugs in hospitals? And, well, these drugs are sometimes given to patients before surgery and it helps doctors to intubate them, you know, put the tube down their throats. It can stop you from gagging. Or if you wake up during, let's say, surgery, it would keep you from moving around so a scalpel doesn't slip.

But because these drugs paralyze the muscles that allow you to breathe, if you're using them in a medical setting, you have to give someone a breathing tube or a respirator. So you're giving them oxygen artificially. Of course, if you give a paralyzing dose of these drugs without putting in a breathing tube and without artificially respiring them, guess what happens? Everything shuts down. They die. They suffocate.

Because they can't breathe. What would it be like to die like that? Incredibly horrible. You're paralysed and you can't move and you can't react and you're suffocating to death. If some of his victims weren't unconscious, they would have felt it. They would have definitely felt it. Oh, just like...

Silent suffering. Yeah, that's right. Because Ian, we talked about it, and he said it would be almost like drowning because you're not anesthetized necessarily. So these drugs don't conk you out or, you know, put you to sleep. So you just can't breathe. And you can't even, like, move or scream. Oh, my gosh. I can't imagine. Awful, awful. Now, it is worth saying that in Efren's confession, according to the cops, he said that he would only do this

to patients who are unconscious. I don't, like, there's no way. All 40 of them? Yeah, I don't know how we can know that for sure exactly. So the cops hold Efren Saldivar on suspicion of murder.

But even though he'd given this detailed confession, admitted to killing dozens of people, in the U.S., that's not enough to go on because of this rule that's called corpus delecti. Yeah, so tell us about it. Body of the crime, tell us what it is. So the corpus delecti, you can't convict someone just based on a confession. Their confession has to actually match some kind of physical evidence. We're basically like, if you took the confession away, you have to still be able to prove that...

They did it by some other means, whether that's physical evidence, circumstantial evidence, other witnesses. But you should not be able to convict someone just by them saying, I did this thing. Yeah. And in this case, all they have is a confession. They don't have...

any physical evidence because these patients really just could have died because they were sick. Yeah, okay. So John, the cops hold him for a couple of days while they're doing some detective work, but in 48 hours, what's he going to come up with? And so they have to let him go. And when he gets out, Efren goes on national television and says that he lied about the confession.

And Sarah, our journalist, told us that Efren basically says... I didn't do it. I was depressed and suicidal and thought this was a way out. And the detective pressured me, and so I don't confess anymore. A way out of what? A way out of life. He sort of gave this idea that he was really depressed and basically suicidal and thought that if...

He confessed to these killings, then maybe he would be given the death penalty and then that would be his way out. Okay. But then he changed his mind, he says. I guess so. I guess so. He also said at the time that he was taking Valium and other sedatives and barely remembered what he said to the cops.

And even a hospital spokesman around that time said, quote, we don't know if anything happened, end quote. Mm-hmm. Mm-hmm. Did he get...

You know, in a room and pressured like it. That's an easy thing to say. Like, do you also say the thing that's been weighing on you? And then all of a sudden when like the gravity of what that means and like what the consequences are, when the gravity of that sets in, the story changes like, oh, maybe I. Oh, gosh, I didn't know what I was like saying. Yeah. But meanwhile, yeah.

The medical board responsible for respiratory therapists suspends Efren's license to practice. So he's no longer working at the hospital. And the cops, cops like John, they're not totally buying that his confession was a lie because it was just so specific. The drugs he used, you know, exactly how he did it. It felt like a weird thing to do.

Just saying. So the cops stay on the case and actually create a task force to find out what is going on here.

And they start going through every patient that died under Efren's watch. And they're looking for suspicious cases. And this is a huge task. It meant wading through more than a thousand complicated medical records. Oh, it was completely crazy. I mean, we're cops. We're not doctors. So we had to learn how to read medical charts and do all that stuff. Quickly trying to become experts at something none of us had expertise in.

But they talk to the doctors and they learn fast. And they're looking for patients who weren't given Pavalon or succinylcholine legitimately at the time of their death, so they didn't need it for surgery. They start looking for patients as well who, at the time of their death, had this particular pattern in their breathing and heart rate that

moments before they died that might suggest they were given Pavalon or succinylcholine. They're also on the hunt for situations like salbiasartrians and the other patients we talked about at the start of the show where they're doing better and then suddenly they die for no clear reason. Mm-hmm, like nosedive, yeah.

And so after months of trawling through these records, they come up with 20 people whose deaths at the hospital were highly suspicious. And so now the plan is to exhume the bodies from a cemetery and search for the drugs that Efren had said he used to kill the patients. And are they the kind of thing that would last for a while?

Like in the system? Like would you still see them? Ashley, that is the question. Because the cops start asking around and they realize that we do not have a good test to find these drugs in this situation. Basically, you can't pull out some easy peasy test off our forensic science shelf and

that would detect what's expected to be pretty low levels of pavillard or succinylcholine in a decomposing human body. So bottom line, even if they exhumed those bodies from those graveyards,

There's no reliable test to find these drugs inside them. They've got nothing. So now what? The story can't end here, obviously. Obviously. They get a tip that there is this place that just might be able to help them.

It's a lab that some call the lab of last resort. What a name. It's where we're at in this story, right? Yeah, true. This lab is called the Lawrence Livermore National Laboratory. It's this huge, sprawling facility in California that was created in the early days of the Cold War. And it's a lab that's been used to

and does some truly bonkers stuff. So they design nuclear warheads. They have one of the world's most powerful lasers. And they also have this forensic science center that can trace tiny amounts of chemicals. Why? What are they doing at this lab? So they use it to find chemical weapons, evidence of chemical weapons in an environment. Oh. And also alleged murderers.

And here's how John describes this slab. I don't know if you know about this place, but it's like, I mean, they weigh you when you go in to make sure your weight is consistent with what's on your ID and, you know, fingerprint you. And it's like a high, really super high level, high security kind of village place.

After the break, we'll get inside that high security village, the lab of last resort. Let's do it. It's coming up.

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Welcome back. Today on the show, I'm here with Ashley Flowers, host of Crime Junkie, and we are cracking the case of Efren Saldivar, a healthcare worker who's suspected of killing dozens of patients wide open.

Let's do it. So we're now heading to the Forensic Science Center at Lawrence Livermore National Laboratory in California. The lab of last resort. And it's now up to some serious nerds to try to detect the tiny amounts of drugs in bodies that have been buried for years. Armando Alcaraz is an analytical chemist who works at Lawrence Livermore. And he was on the team who had to now create this test.

And when he heard about what he had to do, he was like... Oh my God, where are we going to find this stuff? And I was a bit skeptical. I thought it was still going to be enough contamination and at such low levels that we weren't going to be able to see it. And we would then have to sort of pull that needle out of a haystack. So here's what they have to do. Let me describe the needle and the haystack. So needle is the drugs. The haystack...

the loads of other chemicals that would be in these decomposing bodies. Armando told us that some of the patients were smokers, so tobacco would have been contaminating the tissue, so would any embalming fluid used in the burying process. Dirty water would have been seeping into the coffins by now, leaching in all of these chemicals from the soil surrounding it.

And it meant that if you were to look in liquid in their bladder. Yeah, at that point, you don't know whether it was actually real urine or whether water seepage had gotten into that coffin and there was moisture in it. And that's what you're analyzing. Oh, right. You don't even know if it's like body fluid or outside fluid or. Exactly. Exactly.

So they get to work and they quickly realize that one of the drugs that Efren had said he used to kill patients, succinylcholine...

That is basically a lost cause. It's just too hard to identify it in a human body after all this time. And the reason is it breaks down real fast. And when it breaks down into the metabolites, those metabolites can be found in the human body anyway. So how could you go into a court of law and say, well, here we found these metabolites? Well, the defense lawyers are going to go, well, and what does that mean? They're normally found in a human body anyway. But with Pavalon,

There's no reason why a person should have that drug in their system unless they had a procedure or somebody injected them with it.

So they zoom in and try to create a test to identify Pavalon. And because they don't want to be doing this work in human bodies, they start working with something that's pretty close to a human body. Pig pigs. Yes. Yes. So Armando and his colleague get pig livers and they add a tiny bit of Pavalon. Spike it, put the chemical in it and then just allow it to putrefy. Yes.

And then you take it out and homogenize it. You basically put it in a blender and make milkshake out of it. Your face in this moment. I know. It's like the milkshake pig liver. Yeah. You can really feel it in your throat, can't you? Things are about to get a little bit grosser. So because they would take this pig liver Pavillon milkshake...

and in some cases let it sit and decay for months, making it more like what these bodies that have been decaying would be like. At this point, Armando and particularly his boss, Brian Andreessen, are up to their elbows in decomposing pig livers.

Word on the street is that the lab did smell kind of gross. What did it smell like? There's these two notorious chemicals, putrescine and cadaverine. So just the names themselves kind of give you an indication of what it smells like. Cadaverine? Is that what you said? Cadaverine and putrescine. It had to have smelled so awful. I just went into my first morgue for the first time recently and

And there weren't even like, that was bad. I have no clue what this place would smell like. So decomposing bodies, whether it's pigs or humans or whatever, they emit these chemicals. And the two that he talked about, cadaverine and putrescine, they give off that particular smell of death, that smell that you described. And here's how Armando described it.

It's everything awful you could think of that's rotting. That's what it smells like. And so I have to tell you this story because I spoke to Brian and we would be working late at night, you know, trying to get these samples through. And he would be blending these tissues up with the blender. And even though we were doing all this in the chemical hoods, you could still smell that stuff.

and it would penetrate your clothes. It would get into your clothes. And so it would already be maybe 9.30 at night. It was late, you know, and he said, I'm going to go and I'd leave too. He'd go to the grocery store to go buy some stuff to eat. And so he would be standing in line and people would start to just move away from him because he had sort of was, you know, that smell of death was just in his clothes and in his hair and everything.

It stays on you. I've talked to detectives who have said that there are scenes that they come home from and they have to just like burn their clothes or throw away their clothes because no amount of washing will get it out. There is just like a level that is beyond anything I think most people know. Yeah, bad. So while covered with this smell of death, um...

They take the, we're going to go back to the decaying pig milkshakes that have been spiked with Pavalon, and they pass them through this particular contraption that's called a solid phase extraction polymer. It looks a bit like a plastic syringe and it has a kind of filter in it, or what's called a cartridge. And inside it, they're basically trying to separate Pavalon from all the other crap that is in these tissue samples.

But what you have to know is that there's different cartridges out there that are used to isolate different chemicals. I had never thought about how one would isolate chemicals from a human body. Not what I've spent my brain power on. No. And so basically they're pushing all tiny bits of samples through these little syringes. And what the game is to find the exact right cartridge that's going to trap pathogens

pavillon, but leave out everything else or as much as possible of everything else. And so Armando's colleague has been working on finding the right cartridge. Armando's focusing on another piece of this puzzle. It's really tough. Just passing this milkshake through these filters could take days depending on how decayed the tissue is or how much mucus is in it.

May turns into June. They're pulling 16-hour days. It's just late night after late night.

They had that task force that was just sitting there waiting for the results so they could move forward. So that was putting a lot of pressure on us. And that's why we were working late. They're not finding what they need. It's depressing. Nothing is working. No, but what the heck's going on? And so the instrument would start leaking on me, the solvents, and I'd be frustrated and just like pulling my hair out.

But then one day, Brian is testing this cartridge that was designed to detect the residue of chemical weapons. And from across the room, Armando hears his colleague saying something. He goes, I think we're there. It was solid. Actually, what the cartridge did was it acted like a magnet where it would just collect the drug or things similar to the drug and sort of it gripped onto it. And

And then it allowed us to then wash off all of like the tobacco products and other biomaterials that were in the tissue. But the drugs stayed attached. But yeah, that was amazing. That was a magic cartridge. Holy crap. That is incredible. Isn't it? They found the magic cartridge.

So Armando would now extract all the chemicals in the cartridge and then using a bunch of tools like mass spectrometry. Oh, my God. This is why we call it mass specs because there's so many R's in that word. Using tools like mass spectrometry, which separates chemicals based on their weight, and then try to identify Pavalon in that sample. And here Armando catches a break because it turns out that Pavalon creates this really unique signature of

which meant, yes, they can identify this drug. And so now it's time to see if what works in pig livers works in human bodies. So in the spring of 1999, the cops start driving out to the graveyards and bodies start getting exhumed. And John said even for him...

This pulling out bodies from the ground, this was rough. I've seen a lot of dead bodies, but when you exhume a body, it's unnatural. You're pulling the casket out of the ground, you're cracking open the casket, and you don't know what you're going to find. One time we opened the casket, and the maggots inside the casket were jumping out. Like, I can remember them landing on my protective gear on my chest.

Oh, that is rough. That's like not part of the job description. Oh. So the caskets get opened, bodies removed, tissue samples are taken out and then sent to the lab of last resort. Finally, after all this time, Armando and his colleagues start testing their very first patient.

You know, at this point, if they find Pavalon in these bodies, it really does mean, you know, there was no reason for Pavalon to be in their system unless Efren had put it in there. So they start testing patients.

We didn't see anything. I mean, there was no signal. Then the second set of samples for the second patient and there was nothing there. And then, you know, the third one, nothing there. And then I'm thinking, oh, God, what's going on? Is there just nothing in some of these tissues? You start to doubt whether you're going to see anything.

And then they test the fourth patient. And I was like, I got something here. It's there. And so I ran over to Brian. I pretty much ran over there saying, you got to look at this. We got a hit on this. It's confirmed. It's there. It was that, yes, we did it.

So then we were on a roll and we started looking at various tissues from that individual. And sure enough, we were getting positives on the kidney, on the bladder tissue, on the brain. So all of these, that one patient was hot.

Wow. Yeah. They test another body. They don't find it. But then they get another hit and another hit. And they tell the cops, you know, these Pavalon, we are finding it. And John remembers how he felt. So finding the drug was a huge moment. We kind of erupted in clapping and like cheering type of thing. And then finding the drug in multiple patients. That was the then we knew we knew we had it.

They did it. They did it. So do they have to go exhume every single patient that he's ever come in contact with? Or like, where do they go from there? Yeah, so they picked out the 20...

patients that were most suspicious because they couldn't exhume a thousand bodies. So these are the suspicious cases. And do they think that the others truly didn't have it in their system? Like they would have detected that or they're unsure about the other ones? I think we don't know. They could have been killed with succinylcholine.

instead, or it could have been that the pavillon wasn't at too low levels to detect, or it could be that maybe the rest of the patients actually weren't killed by Ephraim. We don't know. That's the thing. When you don't find the chemical, you just don't know what the answer is. But finding the chemical showed that at least with six patients,

There was this drug in there. Wow. Because that's how many patients, that's how many bodies that they found Pavalon in the end. It was six, including Jose Alfaro, who fought in World War II, Salvia Satrian, and Eleonora Schlegel, who toasted to the New Year with her son. Mm-hmm.

And still after this test, the cops actually aren't ready to arrest Efren just yet because this was happening just a few years after the OJ Simpson trial. And that case kind of fell on its face because the cops messed up and mishandled evidence. So I...

So Armando and his colleagues not only test the bodies for Pavalon, but then all kinds of stuff around the bodies. Because there was this suggestion that maybe Pavalon would be in the soil or would have been in the crypt water or the embalming fluid and then made its way into the bodies. And so they test that stuff. Everything's looking fine. You know, when Ian Musgrave, who was our pharmacologist, read details about their work.

He said, and I have never heard an academic describe a paper like this, but he said it was like seeing an experienced figure skater. Every move is smooth and beautiful.

I love that. Someone can appreciate the art. Yeah. Yes. And so in January 2001, this is three years after Efren's first confession, the cops arrest him on his way to work at a construction site. John brings him in for questioning. He tells Efren all the evidence that they have, that Pavalon was found in six bodies. Well, we kept asking them, how many do you think you killed?

Oh, he's very soft-spoken and you can barely hear him. I think sometimes he was, like, writing stuff down and passing notes to us in the interview. And as John remembers it, Efren confesses to killing the patients and at first he won't say how many he killed and instead he tells John what it takes to kill patients using Pavalon and he says, with just one vial...

You can kill a lot of people. Well, I can kill 10 people per vial and I probably had used 10 or 20 vials over the years and so it was probably 100 to 200. What? Yeah. Oh my gosh. Your mouth fell agape when you heard these numbers. Tell me what you're thinking. That's so prolific.

And it's how do you even has he kept a record of who these people were? How do you even go back and try and find out who they were? No, he didn't remember the patients. I mean, he even said that he like lost count at 60 patients. And he can't still be saying like he was like trying to save them from their own suffering, right? Yeah.

So as for the question of why he did it, John actually got... When I asked him, the cop, you know, what do people get wrong when they report this story? And he got quite passionate and he just said, you know, this case has been reported as an angel of death case that Ephraim was trying to reduce their suffering. Mm-mm. But for this case, I mean, John...

says that they were specifically looking for victims who were getting better. You know, like you said, who were toasting New Year's, who wanted to live. And in that confession room, Efren told John that there was a completely different reason for doing what he did. He would get irritated that he would have to go tend to a patient. So bottom line with him was patients were irritants. They disrupted his day.

You know, patients in the hospital are very needy and clicking that button a lot. And so he confessed to killing because of workload. Sir, what did you think you were signing up for? Yeah. You could have worn scrubs at home. What the f***? I don't know if I want to swear on this, but what the f***? Yeah. Yeah.

What? Yeah. He told the police that, quote, it was not something that gave me joy. And then he said, quote, only when I was only at my wits end on the staffing, I'd look at the board who we got to get rid of. What? So callous. We talked to Sarah, our science journalist, about the victims.

There was one woman who actually survived the attempt because he didn't give her enough and she pressed the call button too much and annoyed him. And so he dosed her. There's like, that doesn't even like, that doesn't even like register. I just, like, can someone be that cold? It almost would make more sense if he, you know, did like get some kind of like joy or something from the actual killing. Like that almost makes more sense to me than just being like, well,

Too many people today, so, like, which one's going to lose their life so we can, like, have a manageable schedule? Yeah. Efren took a plea deal and was eventually convicted of killing the six patients that Armando and his colleagues found Pavalon in. Efren was sentenced to six consecutive life terms without the possibility of parole for the murder counts and 15 years to life for the attempted murder of Jean Coyle, who was the woman who survived.

And there is this extra weird twist to this story, Ashley, because if Efren had gone to trial instead of taking a plea deal, he might have been faced with the death penalty. And at that time, if he got the death penalty, do you want to guess? They would have used the same drug. Yes. One of the drugs that they would have used to kill him was Pavalon.

So, Ashley, that's the case of how some nerds used some smooth and beautiful moves to catch a killer. I love it. Science saved the day. Yeah, I mean, I think science is always saving the day, right? Like in the world that we live in,

And I love this because I love the idea that, oh, we didn't know what the test didn't exist. And so instead of being like, oh, sorry, there's something to do. That doesn't mean it can't happen. Science is like happening all the time around us. If we make it happen, just because the test doesn't exist today doesn't mean it won't tomorrow. Yeah, exactly. Thank you so much for joining the show, Ashley. Thank you for having me.

If you want to know more about this case, then go check out our transcript. So in the show notes for this episode, there's a link to our transcript and it's fully cited. So there's links to Armando's amazing work that looks like a figure skater and also links to some amazing reporting that was done by staff at the LA Times who we used to help make this episode. Also, Sarah Skoll's book is...

is called Countdown, The Blinding Future of Nuclear Weapons. And this story didn't make the cut, so it's called Countdown, The Blinding Future of Nuclear Weapons. This episode was produced by Katie Foster-Keys and Joel Werner, with help from me, Wendy Zuckerman, along with Meryl Horne, Rose Rimler and Michelle Dang. We're edited by Blythe Terrell. Mix and sound design by Sam Baer.

Fact-checking by Diane Kelly. Music written by So Wiley, Bobby Lord and Bumi Hidaka. A special thanks to Roland Campos, Steve Wampler, Audrey Williams, the AudioChuck team, Jasmine Kingston, Connor Sampson, Stupid Old Studios and Penny Greenhalgh. Science Versus is a Spotify Studios original. Listen to us for free on Spotify or wherever you get your podcasts. And if you are listening on Spotify, follow us and tap the bell icon so you'll get notifications when new episodes come out.

Also, if you do like the show, we would love it if you would give us a five-star review because it really helps new listeners find the show. I'm Wendy Zuckerman. Back to you next time.