Beware My Brethren (1972)
Led by a sinister minister, a controlling religious sect called the Brethren has taken control of widow Birdy Wemys, sending her unstable son, Kenny, into a spiraling descent into madness and murder. No woman is safe when Kenny's religious mania overpowers him and leads to a rampage of carnage and chaos!
Directed by: Robert Hartford-Davis
Starring: Ann Todd, Patrick Magee, Tony Beckley, Percy Herbert, Suzanna Leigh, David Lodge
Links: IMDb, Movie posters, Movie stills