Active serial killers with monikers, bring out the weird in people. This is one of the reasons, police try not to give them monikers. Unfortunately, it’s a catch-22, because serial killers with monikers are more likely to get caught as the public pays more attention to them. However, when there is a moniker like BTK or .44 Caliber Killer or Zodiac, you get more crackpots. These include the people that will confess to the crimes even though they couldn’t have done it, luckily the police are pretty good at weeding out false confessions these days. It also brings out copycats and the people that probably wouldn’t kill, except they think they can blame it on the serial killer and get away with it. And finally, serial killer groupies are a real thing and often the groupies come out of the woodwork even before the killer is caught and the moniker appeals to groupies.
False confessors are a problem because they waste time. Time that could be spent investigating clues, talking to people that actually know something about the crimes, and it wastes resources, as confessors write out confessions, and attempt to get information from police to add to it, to make them sound more legitimate. As I said though, a good police officer can see through a false confession and knows to ignore it. There are exceptions to this, as sometimes, those confessions sound good, until they do the research on the confessor and learn that he was out of town or something else when one of the victims was killed (this happens more than you’d think).
The second problem is groupies. I’m not sure I understand serial killer groupies enough to explain the psychology. I know some of them have hybristophilia (known as Bonnie & Clyde Syndrome), a condition in which a person becomes sexually aroused by being with a violent criminal (most often murderers and rapists). However, it isn’t a terribly common philia with estimates stating less than 0.5% of the US population having it. This means the majority of serial killer groupies are not hybrisophilies. But may instead buy into the fantasy that they can “change the killer” with their love. This phenomenon has not been well studied, but should be, as thousands upon thousands of women participate in pen pal programs with dangerous criminals and unsavory characters for this very reason. Yet, as far as I’m aware, no serious study by academics has been done on it.
Finally, the biggest problem: copycats. When someone says a serial killer copycat, they automatically assume that the second killer is also a serial killer. This is rarely the case. Usually, its “ordinary, everyday” people that commit copycat murders. They do this, in the hopes that their crime will just be lumped in with the other killer’s crimes allowing them to get away with it. When there is an active serial killer with a moniker in an area, the number of spouse murders increases. Oddly, usually husbands killing wives, hoping that the crime will be thought to be that of the serial killer. During the reign of terror of the Nightstalker Richard Ramirez, there were at least two cases of a husband murdering a wife and hoping it would be blamed on the Nightstalker. And because the Nightstalker crimes were being reported as rapes and murders, both men actually raped their wives after death with inanimate objects to further try to show that the Nightstalker had done it. While both of these men were caught, we don’t know if any other copycat kills were committed where the killer got away with it. After the massacre at the Tate residence, a man killed his wife and children hoping it would be blamed on the same killers that struck in the Tate residence. However, he was unaware of the blood writing on the walls and it was determined to not be related after, a police officer that had responded to the Tate murders said this crime scene seemed less frenzied and less brutal. And for some reason, when a serial killer doesn’t get a moniker copycat killings are less common.
This is why the police try not to give serial killers a moniker and they try to downplay them. Of course, sometimes, this is easier said than done. When Heather Saul killed Neal Falls, the police weren’t really aware they had a serial killer. It was only in hindsight that they began to connect the killings. Having said that, at least one citizens group was investigating the possibility that a handful of murders in Nevada and California were linked to a serial killer. Interestingly, Neal Falls who was killed by an intended victim in 2015, is still only a suspected serial killer as no evidence has been found to link him to any murders. The same citizens group continues to investigate possible victims of Falls, turning the information over to police involved in the cases.