The 1951 film "M" is about the search for a Los Angeles child killer. "M" is about Martin Harrow, a man whose relieves his mental stress by killing little girls. He has killed several whom he has met at various playgrounds and amusement parks. The police department is under political pressure to stop the killings. The police have been raiding criminal underworld businesses and the syndicate chief Charlie Marshall sends his men to hunt down the killer. He hopes to trade the killer to law authorities as part of a deal. The film is set in the summer of 1950 according to calendars displayed. Nothing is said in the film about child sexual molesting. At one point police detectives use a 1940's Walking Liberty half dollar to open a box in Martin's apartment.

Newspapers announce the latest in a string of child killings. All of the victims are little girls, and the killer removes a shoe from each victim. The police use a relatively new invention to disseminate reports to the public.

Most people did not own television sets in 1950 but could watch them at stores. People have become suspicious of men talking to little girls.

In this case, the man accosted at the movie theatre is the child's father. The movie posters shown are for the 1948 film "The Red Shoes", a British film about ballet. Martin's problems began with Mother.

It appears that he didn't get along with her. The police visit the places where grifters, bookies, thieves, and other shady people hang out.

The detectives find some loot but no clues to the killer. The syndicate captains contact their workers to watch for strangers around children and offer rewards for information. Martin has killed again but feels bad about it.

Martin is holding the flute which he plays to attract children, somewhat like in the old fairy story "The Pied Piper of Hamelin" who first used a pipe to cause the town's rats to follow him out of the town and then the town's children. Martin stops at a toy store to watch the model trains and soon is joined by a little girl.

Martin is on a list of suspects because he is a former mental patient. Two police detectives search his apartment.

They find some small trinkets and then spot a wooden box in a closet.

A detective uses a coin to pry open the box.

The coin is a Walking Liberty half dollar and only the reverse is shown.

Silver, 30.6 mm, 12.50 gm
The Walking Liberty half dollar was minted from 1916 to 1947.

The detectives find what they are looking for.

Meanwhile Martin is still with the little girl and some young men spot the couple. One man manages to draw the letter 'M' on Martin's jacket.

The girl tells him about the letter and he begins running and pulling her along, followed by a crowd. He brings her into an office building and they are both accidently locked into a mannikin storage room by the watchman.

Martin tries various methods to open the door. Underworld people converge on the building.

The building they are trapped in is Los Angeles's famous Bradbury Building, built in 1893. The unusual interior design has made it desirable for film location filming and it has appeared in dozens of films.

The wall calendar behind the two men is a Santa Fe Railroad calendar. These calendars had illustrations of cowboys or American Indians and were very popular at the time. The police detectives hear about the Bradbury Building activities and head for the building. The gangsters hold a short "trial" for Martin where he gives a plea that he is "sick", and that his mother was to blame for treating him badly as a child and teaching him that "all men are evil." Gang leader Marshall has a "pet" ex-lawyer who starts yelling that his rackets are just as bad for children. He is silenced by Marshall's gun. The police arrive to arrest Marshall and Martin.

David Wayne as Martin W. Harrow
Janine Perreau as The Last Little Girl
Howard Da Silva as Inspector Carney
Martin Gabel as Charlie Marshall
Raymond Burr as Pottsy
Luther Adler as Dan Langley
Director: Joseph Losey
Writers: Norman Reilly Raine, Leo Katcher, Waldo Salt