Evidence of mutilation and cannibalism highlighted Shawcross' 13-week trial.
In 1972, Shawcross was sentenced to 15 years in prison for killing two Watertown girls. He was out on parole when the series of murders of 11 women began in Rochester. Police said his victims were primarily prostitutes that he raped and mutilated before disposing of their bodies throughout the city.
During his trial, his defense attorneys tried to argue that Shawcross was insane as a result of brain damage, his abusive childhood and his experiences in Vietnam. Shawcross said he heard voices that told him to kill.
However, in interviews with prosecution psychiatrist Dr. Park Dietz, Shawcross said he never heard voices or had multiple personalities. Dietz testified that Shawcross was faking mental illness to avoid prison.
During the murders, he was known as the Genessee River Killer. His case was the subject of the book, "The Misbegotten Son," by Jack Olsen.