This vintage look at outlaws on motorcycles comes to us from I’m a Cop #2 (1954), a title from ME. The motorcycle gang phenomenon was not unknown in those days. Life magazine showed this picture in 1947, when bikers took over a California town.
The Hollister incident was the basis for the movie, The Wild One, starring Marlon Brando, released in February, 1954. My impression from the look of the stick-up men is that the story was influenced by what Brando wore in the movie.
There were no cell phone videos in those days to document how the cop got the confession from the butcher, although we are given a silhouette so we can imagine the carnage.