Experiment in Terror

Experiment in Terror, originally released in the UK as The Grip of Fear, is a 1962 suspensethriller released by Columbia Pictures. It was directed by Blake Edwards and written by Mildred Gordon and Gordon Gordon based on their 1961 novel Operation Terror. The film stars Glenn Ford, Lee Remick, Stefanie Powers, and Ross Martin.

Ripley interviews a woman who implies that shes involved in some way in a serious crime, but before she can give Ripley the details, Lynch murders her. Sherwood continues to be terrorized with phone calls, an asthmatic condition making the unseen Lynchs voice all the more sinister.The FBI identifies the criminal, noting that Red Lynch has a record of convictions for statutory rape, forgery, criminal assault, armed robbery, and murder. They track down his girlfriend, Lisa Soong, whose 6yearold son has just had a hip replaced. Lynch is paying all the hospital bills. Because of this, Lisa refuses to believe that Lynch is a criminal and will not cooperate with the investigation. Ripley nevertheless manages to get some information about Uncle Red from the boy. ........

Source: Wikipedia