Robert Dewey Hoskins, 54, walked away from the Metropolitan State Hospital in Norwalk last Friday. The Los Angeles Police Department said he may be in the Los Angeles area.
Hoskins was convicted of stalking Madonna in the '90s. After serving a 10- year prison sentence, he was transferred to Atascadero State Hospital, where he was found to be a mentally-disturbed offender.
He is said to be highly psychotic when he is not taking his medication and has violent tendencies.
The LAPD says Hoskins has also threatened actress Halle Berry. According to celebrity web site TMZ.com, Hoskins threatened to slit Berry's throat.
TMZ.com said Berry is asking a judge for permission to move to France with her daughter for safety because she is fearful for herself and her child, but Gabriel Aubry, the child's father and Berry's ex-boyfriend, is reportedly against the move.
Hoskins made a similar death threat against Madonna and was shot by her bodyguard in 1995 when he was discovered trespassing on her property.
When Madonna testified against Hoskins in 1996, the singer said she was "incredibly disturbed" to be in the same room as him.
Because Hoskins is considered dangerous, authorities are asking anyone who sees him to avoid any contact and call the LAPD Missing Persons Unit at (213) 996-1300.