The Unguarded Moment (Harry Keller, 1956)

This strange film begins like a slasher, four years before Hitchcock’s Psycho. A woman is found dead, killed in some unseen but brutal fashion by a man. A policeman on the scene talks of waves of such killings, which come and go without rhyme or reason. Though no one explicitly states this, the phenomena has the ring of an all too familiar societal problem, and Lt. Harry Graham (George Nader) alone cannot resolve it. However, by then focusing on the next would-be victim, the film returns to the relatively more blinkered perspective familiar from the slasher film; after all, whether the person now stalking and threatening this woman is a product of wider social attitudes or merely a crazed murderer should make little difference to her.