Kelsey Grammer is to confront the man who raped and murdered his sister in an attempt to prevent the killer's release from prison
The star of TV's Frasier will come face to face with Freddie Glenn at a parole hearing in January.
Grammer will tell the parole board of the anguish he has suffered since his sister Karen was killed in 1975.
The 18-year-old student was abducted, raped and her throat was slashed.
Grammer, 20 at the time, had to identify the body.
The killing plunged Grammer, who plays quick-witted psychiatrist Dr Frasier Crane in the U.S. comedy series, into a spiral of drink and drug abuse.
The actor has only recently come to terms with the tragedy, which he has admitted changed his life.
Glenn has served 31 years of a life sentence in a Colorado jail but Grammer is determined he remain behind bars.
"Recently, I got news that the man who did this to Karen is now eligible for parole," he said.
"There is a hearing sometime later this year that I will attend. I am angry about him. "I never had the opportunity to speak for my sister before. I will now."
Grammer, 52, has rarely spoken about his sister other than to admit the devastating impact her death had on his life.
He was an aspiring actor living in New York when he had to identify her body.
Karen, a college student, had been abducted after leaving a fish restaurant in Colorado Springs, Colorado, where she had gone to see her boyfriend.
Glenn, Michael Corbett and Larry Dann raped her and then Glenn slashed her throat with an army bayonet and tossed her into the street. She crawled away looking for help but bled to death.
The prosecutor in the case and lead detective appealed against Glenn's parole last year when he first became eligible for release.