SACRAMENTO (CBS13) — Convicted serial killer Roger Kibbe was killed behind bars Sunday. His victims’ families say it’s deserved.

Kibbe, known as the “I-5 Strangler,” was serving consecutive life sentences for killing at least seven women over two decades.

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Vito Bertocchini is the former lead homicide detective with the San Joaquin County Sheriff’s Office.

“This is evil killing evil. That’s what it is,” Bertocchini said.

Bertocchini spent 24 years investigating the Kibbe case, eventually getting him to admit to the rape and murders of at least seven women. He believes there are more victims tied to the murder spree.

“Absolutely. He’s responsible for many more,” Bertocchini said.

He remembers the last conversation he had with Roger Kibbe in 2019.

“He was scared to be on mainline. He was worried that somebody would make a name for themselves by attacking him,” said Bertocchini.

It’s not clear if that’s why​ Kibbe’s life ended Sunday. Kibbe, 81, was found dead in his prison cell. His cellmate, 40-year-old Jason Budrow, is now accused of killing him.

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Budrow was serving a life sentence for first-degree murder out of Riverside County for killing a woman he dated.

Lou Ellen Burleigh (credit: Carl Burleigh)

Carl Burleigh’s sister Lou Ellen Burleigh was Kibbe’s first known murder victim in 1977. She was just 21 years old.

“I don’t have any sympathy for him at all,” said Burleigh told CBS13 on a video call from Seattle.

Their mother Wilma, now in her 90s, says they try to keep Lou Ellen’s memory alive to this day.

“He chose to kill and I can’t really hate him. I just feel regret. I just don’t spend much time being angry, I think he’s being taken care of,” she said.

For Bertocchini, who dedicated his life to this case, he says he’s worried that it may be too late now to get answers for other victims’ families.

“[Kibbe] made a comment a long time ago: ‘I have two cans in my head. I’m opening the lid to one can and letting some secrets out, the other can, you’ll never get that lid open,'” Bertocchini said.

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Roger Kibbe’s cause of death is not yet known but law enforcement is calling this a homicide investigation. Budrow has been moved to an administrative segregation unit.