Cage of Evil 1960

While investigating a diamond heist, disgruntled cop Harper falls for Holly, the top suspect's main squeeze. When she convinces him to kill her boyfriend and make off with her and the loot, they start down a treacherous path full of dark surprises.

Cast:

Ron Foster
Det. Scott Harper (as Ronald Foster) 

Patricia Blair
Holly Taylor (as Pat Blair) 

Harp McGuire
Det. Murray Kearns 

John Maxwell
Insp. Daniel A. Melrose 

Hugh Sanders
Martin Bender 

Helen Kleeb
Mrs. Melton