Sharon Tate's sister has opened up about the tragic actress' horrific murder 45 years after her death, confessing she will never get over the pain of losing her. Debra Tate was just 16 when the pregnant Valley of the Dolls star was slain by convicted mass murderer Charles Manson and his cult of followers in August, 1969, and she admits she still has difficulty coming to terms with Sharon's death. She tells America's People magazine, "It's hard to determine if it's a dream or if you're awake. "The ones that are left behind are victims as much as the actual victims. We are here to suffer for years and years to come." Debra, now 61, has become an outspoken campaigner for victims' rights and she credits the tragedy with giving her a new purpose in life, saying, "It made me what I am." She has also made a point to attend every parole hearing for her sister's murderers in a bid to keep them behind bars, and even though their pleas for freedom force her to "relive it all", she insists she finds satisfaction in ensuring "these people stay in prison for the rest of their lives". She adds, "The people that we lost in this historical event were real, and they had lives and families. They're sorely missed." Cult leader Manson was denied parole for the 12th time in 2012, when California prison officials ruled he still posed too great a danger to the public to be released. Debra recently released a photo book dedicated to her sister's life, titled Sharon Tate: Recollection, which featured an introduction written by the late actress' director widower, Roman Polanski.