Night of the Bloody Apes (1969)

Dr Krallman, is a prominent surgeon whose only son Julio is dying of a severe heart infection. Dr Krallman decides to operate on him, transplanting the heart of an ape in him, but this turns the young man into a half human/half beast that commits several rapes and murders. When Dr Krallman tries to remedy his mistake and does another operation, but it is too late. Can the authorities stop Julio before he strikes again?