This is probably from watching way to many profiling style crime dramas, but do serial killers ever just stop like this? I thought they typically escalated until they were caught.
If he's the Monster of Florence too, he didn't stop at all. He just moved to Italy, and kept killing people (the first documented murder there is just some months after he left the US)
Sure, Dennis Rader (BTK) did. He only resurfaced over a decade after his last murder because he started taunting police again, either because he got bored or he wanted recognition.