This is one of very few episodes of the series not to feature a humorous ending comment from Hitchcock. He said that the problem of youth gangs should be taken seriously, so he doesn't do a silly concluding scene, although his opening and the comment at the midpoint are humorous.
Harlan Ellison's story and teleplay were based on his own real-life experiences in street gangs. In an interview on The Tom Snyder Show, Ellison said he had joined a gang simply to follow Hemingway's dictum to "write what you know about." He wound up being nearly killed in a knife fight, and Ellison was left with a permanent scar on his wrist that he showed to Snyder.
Zalman King plays a character named Fish. In the first draft of Harlan Ellison's script for The Outer Limits episode "Demon With a Glass Hand," the main character of Trent is named Mister Fish.