Former Manson "family" member Leslie Van Houten has gone into detail about her involvement in the 1969 murders she participated in at the order of cult leader Charles Manson.
Speaking during her 20th parole board hearing, Van Houten said she has dramatically changed her life since the crimes.
"I know I did something that is unforgivable, but I can create a world where I make amends," Van Houten, now 63, said.
"I'm trying to be someone who lives a life for healing rather than destruction."
Van Houten was convicted of murder and conspiracy for her role in the slayings of wealthy Los Angeles grocers Leno and Rosemary La Bianca.
The La Biancas were stabbed to death the night after Manson's followers killed actress Sharon Tate and four other people, but Van Houten did not participate in the Tate killings.
Van Houten, 17 years old at the time of the murders, had been a homecoming princess and led a promising life until she became addicted to drugs and joined Manson's murderous cult.
She said she had felt left out after not taking part in the Tate murders, and volunteered to go along the next night.
Describing her role, Van Houten said Manson "could never have done what he did without people like me".
After 44 years in prison and extensive therapy and self-examination, she said she realises that what she did was "like a pebble falling in a pond which affected so many people".
"Mr and Mrs La Bianca died the worst possible deaths a human being can," she said.
Attorney Michael Satris argued his client has totally reformed herself in prison.
"Everything she does is for humanity," he said.
Los Angeles County Deputy District Attorney Patrick Sequiera countered, saying some crimes are so heinous that they may be worth an exception to the legal guarantee of the possibility of parole.
Surviving relatives of the La Biancas attended the hearing to voice their opposition to Van Houten's parole.
Asked to explain her past actions, she said: "I feel that at that point I had really lost my humanity and I can't know how far I would have gone. I had no regard for life and no measurement of my limitations."
Van Houten has earned two college degrees while in prison at the California Institution for Women and has been praised for her work helping elderly inmates.
Her bid for parole was denied.
Other members of Manson's murderous "family" have lost their bids for parole.
Manson, 78, has stopped coming to parole hearings, saying prison is his home and that he wants to remain there.
