Based on

Movies like Creature with the Atom Brain (1955)

Murders, with victims dying from spines broken by brute strength, erupt in the city and the killers, when encountered, walk away unharmed by police bullets which strike them. A police doctor's investigation of the deaths leads to the discovery of an army of dead criminal musclemen restored to life, remotely controlled by a vengeful former crime boss and a former Nazi scientist, from the latter's laboratory hidden in the suburbs.