He Walked by Night (1949)

Roy Morgan is a burglar who listens in to radio police calls, allowing him to stay one step ahead of the cops. After Morgan kills a police officer, Sergeants Brennan and Jones have little success in putting the clues of the case together. But when Jones is wounded in a shoot-out with Morgan, Brennan employs all facets of detective work, including forensics and informants, to find the elusive and clever criminal.