Kroft on interviewing a serial killer

Steve Kroft and 60 Minutes producer Graham Messick discuss their extraordinary jailhouse interview with convicted serial killer Charles Cullen

The story of convicted serial killer Charles Cullenrepresents the ultimate "insider threat," says 60 Minutes producer Graham Messick. "This is what can happen if somebody who is inside betrays all the trust that's given to them."

For anyone who has entrusted a loved one to the care of medical professionals, the Charles Cullen case is your worst nightmare. He masterfully played the role of caring nurse, while quietly injecting countless innocent patients with lethal doses of medication. It's unclear how he selected which patients to murder, and it's unknown how many victims died at his hand.

Messick and Steve Kroft conducted an extraordinary jailhouse interview with Cullen for the 60 Minutes broadcast this week in an attempt to understand why Nurse Cullen murdered his victims-- and, more importantly, why various hospital administrators couldn't stop him.

"It takes a really subversive, devious mind to break all the rules and actually use that to commit the worst crime of all," says Messick. "When we interviewed him -- and he's been in this particular prison for nine years -- I thought we were gonna see somebody who has really come to grips with what they'd done. He hasn't.

What did you think of Steve Kroft's interview with convicted serial killer Charles Cullen?