Due to the graphic nature of this killer's crimes, listener discretion is advised.

This episode includes discussions of murder and assault that some people may find offensive.

We advise extreme caution for children under 13.

Detective Superintendent Stuart Clifton's blood ran cold,

when he realized he would have to let a child killer go free.

The unflappable Yorkshire-born detective thought surely this 22-year-old nurse would crumble

under police interrogation.

But Beverly Allit seemed almost bored by police efforts

to force a confession.

She asserted her innocence so fervently

that one investigator had to leave the room to clear his head.

Allet was present for every suspicious death at the hospital.

She had access to insulin, which Clifton suspected was the murder weapon.

The deaths on Ward 4 started when Allet began work, but Detective Clifton had no hard evidence.

And so the police released Beverly Allet on bail. As Beverly

walked back into a world full of potential victims, Clifton's hopes now

rested on a single vial of blood.

Could it give him the proof he needed to put Beverly away

before she killed another child? And this is serial killers.

Hi, I'm Greg Polson, and this is serial killers.

Today we finish our deep dive into the life of Nurse Beverly Allet,

who murdered at least four children

...