These types like BG use trickery to fool their prey.
The trickery may have been how he was dressed, or camoflouged, to blend in with his surroundings. It could be a lure he used to confuse the girls. Without some sort of trickery, I am not sure he would have been successful and been able to move on without anyone noticing.
It is getting slow, I know. Camouflage and deception are interesting to me, looking at previous crimes where innocents were targeted for an internal motive only known to the aggressor. In the past, there have been stalkers who feigned an injury to develop sympathy in their targets, those who developed a "ruse" to gain acquaintance with their targets, such as needing to use a phone, and others who used one victim against the other, in a false scenario where both would be OK in the end.
This is all IMO, but some things I was thinking about tonight.
Many years ago, I dated someone who grew up in Queens, NY, and who worked night shifts in fast food places in between college classes. This caused my friend to have to walk the streets and ride the subways very late at night or early in the morning.
Grad school brought my friend to my city, where the crime rate was not even a fraction of what Queens saw.
One night as we were driving home after a movie, we saw a person sprawled across the road in the intersection ahead of us. I sped up to pull over and help, but my friend insisted that we not because it could be a scam. My friend said that of course we should call 911 but we should not stop.
I was dumbfounded at what seemed like a mean and callous attitude and a lack of compassion. I understood the point, but I just couldn't believe that anyone would go to those lengths to lure someone in.
Years later when I thought of that night, I realized that my friend was absolutely right. I never learned if the person was genuinely hurt, and although I hated not being to react instinctively, I do think we did the smarter thing.
In broad daylight with people around, I will help someone who appears​ to have fallen or who has had medical emergency. I just did two such things in the last couple of weeks, but for sure, both times my friend from Queens crossed my mind.
Sometimes I find myself thinking that it's a shame that we have to think this way now. In actuality, I think we've probably always had to think that way but that we often didn't.