He would scope out the kids from their cloths to mannerism to see if they where economically challenged.
He would look at their parents, if the dad seemed like a threat he would back off.
He would look at friends and see if they where close and if the kid would talk if he tried something.
He would get close by congratulating a kid or tying to talk to them when it seemed like an appropriate time, to initially start grooming by being over complimentary.
He would see if they had family issue or educational issue and if he could help out.
He basically says with todays social media he would have destroyed more lives then he already did (300 lives he says)