Cawley

In the short story The Red Signal, Cawley is a police constable assisting Inspector Verall in the investigation of the murder of Sir Alington West. When they arrive at the apartment of their suspect Dermot West, Verall instructs Cawley to search the place and he finds a revolver. Later, the inspector has to go off. he leaves Cawley behind with Dermot (who is pretending to be his own manservant Milson. Dermot manages to escape on the pretext of going to the kitchen to make Cawley a cup of tea. Once in the kitchen, he escapes via a wire basket used for trade deliveries.

Portrayals
In the episode The Red Signal of The Agatha Christie Hour, a TV film adaptation of the story, the part of Cawley is played by Andrew McCulloch. Here he has a few more lines and a slightly more active role than in the original. He does the search and finds the revolver as in the original. When Verall leaves him behind to watch Milson (Dermot), Cawley is the one who suggests that he would like a cup of tea. He actually follows Dermot into the kitchen. Cawley tells Dermot he was just about to go home when he was called for the case. Dermot suggests that he might want to make a phone call to tell someone he would be late home. When Cawley leaves to make the phone call, Dermot takes the opportunity to escape.

Cawley is also present in the final scene, the climactic confrontation with the true killer of Sir Alington but doesn't get any lines here.