Detective Sergeant John McKillop

They would have definitely felt it.

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.

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.

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.

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.

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.

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.

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.

I was a sceptic because it just seemed odd.

The whole thing seemed odd.

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.

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.

Yeah, exactly.

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.