Why was the Zodiac killer never caught?
Crimes are easily solved when there is a connection to the victim and the murderer. The Zodiac Killer killed at random and in wide areas. (There are a lot of random killings that go on today that are hard to find the murderer) Because it was the 60s and the lack of DNA evidence it was hard to identify him. He also struck when there were no witnesses and a dead body can’t give a description of the killer. And the ones that survived never saw the face, because he hid his face. Those are the basic reasons, he is also believed to have died, And because the prime suspect died (never charged) it will be impossible to know if he was the killer.
The evidence never really pointed to a certain person to be able to bring them to justice, where they would have been able to prosecute him. Cold cases such as this are always going to be of an interest to both the detectives/police who investigated it, so much so that I don’t think that they will ever truly let it go. There has always been speculation that the guy who was the Zodiac Killer died. Also there has been speculation that he may have gone to prison, that is always possible that he could have gone to prison. But again both of these ideas are only speculation. They mystery goes on.