Two four year old twin girls are missing, and Friday and Smith have been assigned to the case. They at first hoped the girls simply wandered off, until evidence started coming in that they had been abducted. They visit a registered sex offender (they had those in those days too), who is none too friendly, but he's cleared. The girls are later found alive, but had been molested. Theyre too shaken up to give a description. The mother is grateful for their return, saying it's all over, but Friday reminds her the culprit is still on the loose. A real estate agent gives a description of a vulgar man talking dirty in front of children, and got his license plate number. Friday and Smith have it traced, and visit the apartment of the man. He is obese and slovenly, and hostile. After faking hospitality, he slugs Smith with a wine bottle, resulting in a facial cut, then Friday beats him up. The creep cries, and expresses gratitude that he didn't have his knife at the time of the abduction, or he would have killed the girls. Then it's off to headquarters.
Child molestation wasn't talked about much on television in the early 1950s, but Dragnet dealt in reality.