In October 2000, Obara was charged with drugging, raping and killing Blackman, as well as with raping eight other women and the manslaughter of Ridgway. His trial began on July 4, 2001, and on April 24, 2007, he was jailed for life on multiple rape charges and manslaughter, but was acquitted of Blackman's rape and murder due to a lack of direct evidence. Evidence supporting his guilt of rape included the approximately 400 videos he took, which showed him engaged in date rape activities (including one with Ridgway). For the charge of manslaughter, the prosecutor produced an autopsy report showing traces of chloroform in Ridgway's liver and a paper trail showing that the accused accompanied her to the hospital before she died. In Blackman's case, however, the prosecutor could not produce any forensic evidence linking the accused to her death. Even her cause of death could not be determined.