Killer Women with Piers Morgan

I really felt I was with someone just evil

She may look like the girl next door but Erin Caffey was the mastermind behind the murder of her mother and two younger brothers at the age of 16.

Erin's boyfriend and his friend brutally beheaded her mother and attacked her father and brothers with guns and machetes at her request - and he wasn’t the first person she’d asked to do it.

Criminal therapist Israel Lewis worked on the case and joins us live from Texas to talk about the girl he initially believed to be "beautiful inside and out". He now regards Erin as one of the best liars he's ever come across, describing her as "incredibly convincing".

Despite being "riddled" with bullets, Erin's father survived the attack by crawling out of the house before it was burnt down. He has shown "extraordinary forgiveness" and now visits his daughter in a high security prison in Texas, where she has spent the past eight years.

Piers interviews Erin - now 24 - as part of his new documentary series, Killer Women with Piers Morgan, which follows his interviews with three of America's deadliest women.

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Don't miss Killer Women with Piers Morgan this evening, 9pm, ITV