♪ >>> my name is deborah tate. iddle sister to sharon tate. >> juju: sharon tate, a model and budding hollywood movie star best known for her breakout role in "valley of the dolls." >> let's face it. all i know how to do is take off my clothes. >> juju: she was building her family with famous director roman polanski when the unthinkable happened. >> she was physically perfect. but more important than that, she was an absolutely beautiful soul. had a wicked sense of humor. >> juju: deborah tate speaking exclusively to abc news saying the killing of her sister and others by members of the manson family changed the lives of her loved ones forever. >> my dad retired from the military. he went out on his own quest to find the killers. it affected everything. >> juju: deborah has made it her life's mission to help keep the manson family members behind bars, including the newly released leslie van houten, who was not directly involved in her sister's murder. >> is she a nice girl? no. we're talking about one of the most mu