He Walked by Night (1948)

"When a police officer is gunned down by a man whom he had stopped to question, a city-wide dragnet fails to catch the shooter, leaving the police with only minor clues to go on. Later they discover that the same man has been selling stolen equipment through an electronics dealer, and they set a trap for him. But he shoots his way out of the trap and escapes. The police must piece together a description of the man's appearance and habits from witnesses and a few small clues, as they search untiringly for a dangerous and very resourceful criminal."