>>511996411 (OP)
There are estimated to be at least 50 active serial killers in the US, and potentially many more.
There are multiple active serial killers working as long haul truckers, and clusters of unsolved murders indicating a serial killer in most major cities.
Despite what people think, the homicide rate has dropped from over 90% in 1965 to barely 50% today. A big part of that is due to large numbers of black on black inner city drugs/gang related homicides, that no one really cares about enough to put a lot of effort into solving, and all of the potential witnesses do not want to cooperate. But this also makes it easy for serial killers to blend into that and fly under everyone's radar.
Most murderers get caught because there is either a direct connection/motivation between them and the victim, and/or are retarded and make the most basic mistakes that lead to them getting caught. Even supposedly "smart" murderers like Kohberger or Mangioni made tons of idiotic blunders that allowed the police to identify them almost immediately.
If someone went out and murdered a random person that they had no pre-existing connection to, and took the most basic precautions, there is almost no chance that they would get caught.