On the night of August 10, 1969, he rode with members of the Manson family. Charles Watson, Patricia Krenwinkel and Leslie Van Houten were dropped off at the house of Leno and Rosemary LaBianca, but Grogan, Manson, Susan Atkins and Linda Kasabian continued to Venice Beach where, according to Kasabian, Manson sent Grogan, Atkins and Kasabian to kill actor Saladin Nader, but Kasabian, according to her own account, intentionally led them to the wrong apartment and the plan was aborted.
Grogan later helped Manson, Watson and Bruce M. Davis kill Spahn ranch hand Donald Shea. The jury returned verdicts of life imprisonment for Manson and Davis, but death for Grogan. However, on December 23, 1971, Judge James Kolts stated that "Grogan was too stupid and too hopped on drugs to decide anything on his own" and that it was really Manson "who decided who lived or died" and reduced Grogan's sentence to life imprisonment
Steve "Clem" Grogan, was paroled in 1985.
