March, 2021 A California serial killer who authorities say strangled and raped at least seven women was fatally choked himself in a state prison, officials said Wednesday.

Roger Reece Kibbe, 81, known as the “I-5 Strangler” in the 1970s and 1980s, was spotted unresponsive Sunday in his cell at Mule Creek State Prison southeast of Sacramento — his 40-year-old cellmate standing nearby.

An autopsy showed Kibbe had been manually strangled, the Amador County Sheriff’s Office said, calling the death a homicide.

No charges have been filed in the death of Kibbe, a former suburban Sacramento furniture maker whose brother was a law enforcement officer.

He was initially convicted in 1991 of strangling Darcine Frackenpohl, a 17-year-old who had run away from her home in Seattle. Her nearly nude body was found west of South Lake Tahoe below Echo Summit in September 1987.

Investigators said then that they suspected him in other similar slayings.

But it wasn’t until 2009 that a San Joaquin County District Attorney’s Office investigator used new developments in evidence to connect him to six additional slayings in multiple Northern California counties, with several victims found alongside Interstate 5 or other highways in 1986. Kibbe was serving multiple life terms for the slayings when he was killed.

Authorities said they never stopped trying to prove that he was responsible for even more deaths. Investigators secretly took him on multiple field trips from prison with the hope that he would reveal the whereabouts of more victims.

They would buy him an egg McMuffin and a Coke for breakfast, another Coke and a hamburger and fries for lunch, Vito Bertocchini, a retired San Joaquin County sheriff’s detective and district attorney’s investigator, told The Sacramento Bee.

Bertocchini spent nearly two decades pursuing Kibbe and thinks he must have killed others during the 10-year gap between his first and last known slayings. Investigators have said they found other women who had been killed and dumped with Kibbe’s trademark of cutting his victims’ clothing in odd patterns.

He was finally captured after Sacramento police said a would-be victim escaped and they recovered a garrote made from a pair of dowels and parachute cord along with scissors and other items.

Investigators said they matched the cord to rope found with Frackenpohl’s body and at Kibbe’s house, all with microscopic dots of red paint. DNA eventually linked him to two other victims, and he agreed to cooperate in exchange for prosecutors taking the death penalty off the table.

Kibbe never admitted to other killings beyond those with which he was charged, but Bertocchini said he never stopped trying to elicit another confession.

Even after he retired in 2012, each year he sent Kibbe birthday and Christmas cards, asking him to speak up if he recalled anything about other victims. He and his old partner last visited Kibbe in prison in 2019, but still he wouldn’t admit to any more victims.

Now it’s too late, but Bertocchini called Kibbe’s death by strangulation “some fitting justice.”

“I don’t wish ill on anyone,” Bertocchini said. “But I hope he remembered every one of his victims while he was being killed.”