Weedman's son, Jonathan, said the 86-year-old criminal defense lawyer died Wednesday night after a five-year bout with Parkinson's disease.
Longet, whose wispy beauty and French-accented singing voice gained her a following, was charged with manslaughter in the killing of Olympic skier Vladimir "Spider" Sabich in Aspen, Colorado, in 1976.
Weedman, a highly respected member of the Los Angeles bar, was summoned in 1977 to defend Longet. The case was a harbinger of sensational celebrity cases to come as members of the news media from around the world crowded into the ski resort and overflowed the tiny courtroom.
The defense achieved a legal victory as the jury convicted Longet of the lesser charge of criminally negligent homicide, a misdemeanor. Weedman argued the shooting was an accident and called both Longet and her ex-husband, singer Andy Williams, to testify.
Longet was sentenced to 30 days in jail, which she was allowed to serve on consecutive weekends. She later married the local co-counsel on the case, Ron Austin.
Weedman is survived by his wife, Judith Newman Weedman, and sons Jonathan, Robert and Jeffrey Weedman. Services will be private.