Kelsey Grammer opened up about his younger sister's brutal killing in the most recent issue of Vanity Fair.

Karen was just 18 years old in 1975 when she was abducted by four men, raped, and fatally stabbed by Freddie Lee Glenn. Grammer faced his sister's killer at a parole hearing last July.

"I miss her in my bones," he wrote in a letter to the parole board, opposing Glenn's release. "I was her big brother. I was supposed to protect her—I could not.... It very nearly destroyed me."

The 60-year-old also addressed Glenn directly in a video conference during the hearing. Glenn, 58, expressed remorse and apologised for his actions.

"I accept that you actually live with remorse every day of your life, but I live with tragedy every day of mine," Grammer responded. "I accept your apology. I forgive you. However, I cannot give your release my endorsement. To give that a blessing would be a betrayal of my sister's life."

The Emmy Award-winning actor discussed self-medicating with drugs and alcohol to cope with the guilt and grief he felt following the death of his sibling. As the older brother, he lamented that he did not protect her, although he was miles away at the time of her death.

Currently sober, Grammer has a new wife of four years, and two young children. The actor has four other children from prior marriages.

Grammer is currently starring in the Broadway production of "Finding Neverland," based on the popular film about the author of "Peter Pan."

Glenn will be up for parole again in 2017, and Grammer said he will continue to oppose his release.

"... I believe the gift of life and freedom he took from my sister precludes him from ever being allowed to enjoy that gift for himself," he told Vanity Fair.

"He took her future from her with no regard for her whatsoever. He assumed he had a right to do so. He assumed she was his property, and that the precious gift God gave her was his to take."