The Devil Man by Edgar Wallace

Peace waited until he had turned the corner, crossed the High Street quickly, and, taking cover behind two stout women who were moving in his direction, kept the man under observation.

There was a possibility--a grave possibility that if Carton was too much terrified he might blab. The man walked on. He had already located his shadow, and took a bold step. A policeman was standing under the railway arch, jotting down notes in his book. Carton walked up to him.