Shoot First (1953)

U.S. Army Lt. Colonel Robert Taine and his wife Cecily live in a village in England. While hunting on some land he has recently purchased, he shoots a load of buckshot at a man he thinks is a poacher but, upon examination, he discovers the man is dead and believes,at first, he has killed him. With the police and the Secret Service chasing him, he trails a suspect to London and this leads him to an espionage gang.