70's Film: Patients Kill Guard and Escape Insane Asylum

by Mario DeLara
(Pennsylvania, USA)

Does anyone remember this 70's film about an insane asylum?

Mental patients in white gowns sneak in and kill a guard or doctor by sticking a broken glass or bottle top into his eye socket.

The newly freed patients walk around the sylum grounds and the leader eventually escapes. This part was shot in an almost black and white sequence, however I recall a reddish tone to the film at that point, almost like a flashback darkened sequence.

Help!