Serial killer nurse Charles Cullen speaks out in first TV interview

Published: 4:55 PM EDT Apr 29, 2013   Updated: 6:00 PM EDT Apr 29, 2013

Charles Cullen is one of the most notorious serial killers in U.S. history.

Last night, the CBS program "60 Minutes profiled the former hospital nurse in his first, and only, television interview.

Cullen was convicted of killing 22 patients at seven hospitals in New Jersey and Pennsylvania, but he said he killed at least 40 patients over a period of 16 years.

"He knew when he did this he was going to cause pain to these people. He knew it, and he did it anyway," said Mark Altemose, an attorney who represented the families of 17 alleged victims, five of whom died at St. Luke's Hospital.

Those five were part of Cullen's conviction almost 10 years ago.

"It's a nightmare. I don't know how to put it any other way. These were good people who've had horrible things done to them," Altemose said.

In the "60 Minutes" interview, Cullen talked about why he killed.

"Did you get pleasure out of it"? asked CBS's Steve Kroft.

"No. I thought these people weren't suffering anymore. So in a sense, I thought I was helping," Cullen replied.

"That is ridiculous. The lion's share of the clients we represented were not seriously ill," Altemose said. "In fact, many were improving. Some were about to be discharged from the hospital."

Altemose said he's already had to console several clients badly shaken by the interview, in which Cullen admitted he should have been caught long before he was.

"At St. Barnabas, they could have had my license investigated and probably revoked at that point in time," Cullen said.

 "Should they have?" Kroft asked.

"Should they have? Yes." Cullen responded.

When Cullen was hired at St. Luke's, he'd been fired or forced to resign from five other hospitals. By then, he said he killed 11 people and five more at St. Luke's.

He said St. Luke's gave him a neutral letter of recommendation to leave.

"Do you think they knew what you were doing at St. Luke's?" Kroft asked.

"I think they had a strong suspicion," Cullen answered.

That was not proven in court. A St. Luke's spokesperson said the hospital is working on a statement.

The "60 Minutes" report did say Cullen's transgressions were not in his file prior to working at St. Luke's.