From personal experience as a victim of a creepy, juvenile stranger, part of the problem seems to be that none of these agencies/people seem to be talking to each other (and probably due to law, I’m sure).
Not so much as you'd think, the problem is even the law has constraints, and with HIPAA laws its a thin line what can be shared and what cant .
Once it becomes a medical/psychological issue, its pretty much out of LE's hands (as it should be, were not the ones who know how to treat these individuals, just how to apprehend them)
Some in the psychiatric community tend to take it as an insult when LE doesn't seek their help in apprehending a suspect, theres scores of stories of psychiatrists, and psychologists, rendering psychological profiles only to not be wrong, but to have in some cases, lead an investigation astray (ive had that happen) but that's not what they are good at , their expertise is treating them... we cant do that .
When it comes to eyes on it starts with those who are around them most, and theres ALWAYS a history, always red flags always someone who knows, or knew, or strongly suspected .
When your 12 yo has no friends, but is coming home drunk or high, ..... may want to pay attention, especially when it happens more than once .
When your 14 year old is caught exposing himself to other kids , ......you may want to pay attention.
When the police bring your 18 year old home after he's caught peeking in the windows of a neighbor, while masturbating, ........you may want to pay attention.
When your 11 year old is catching birds, putting them in a box so he can light it on fire , ........you may want to pay attention.
When you find several pairs of women’s underwear hidden under clothes in your sons drawer, , and he has no known romantic attachments EVER, ...........you may want to pay attention
And when your 15 year old son is bringing home dead animals from the roadside, dissecting them in a shed, and putting their bones and entrails on stakes in your backyard, and taking pictures .............YOU MAY WANT TO PAY ATTENTION!
Now, You'd think any of these would be a glaring beacon to any parent, but literally all of these are true accounts of events in the early lives of serial killers.