Technology has made it massively difficult to be a successful serial killer nowadays. You'd have to move like a ghost with no phone, a car without gps, access to multiple vehicles. Any body would have to disappear which would lessen the chance of a dna link, you would have to burn the body, bury it, feed it animals etc. Then you would be lucky to not get picked up on a random street camera picking up the victim. You would need to know the location of a surveillance cameras in the area. Its simply too much work.
The dumbest serial killer to get caught had to be the BTK killer. Dude sent a floppy disk that had metadata on it to the police. They used that to track him to the church he was president of
. Send the police digital communications brehs