Green for Danger (1946)

Alistair Sim stars as one of the original annoying but brilliant detectives, perhaps influencing the later portrayal of Columbo on tv by Peter Falk. Based on the novel of the same name by Christianna Brand, this excellent bw film features strong directing, a varied and dynamic (for English actors) ensemble cast, and practically perfect pacing over its 91 minutes to keep the audience absorbed in this procedural/whodunit. Highly recommended.