I'm agreeing with your excellent prediction, ab01, above.
I believe he has attacked people before though.
He might have even "failed" in those attacks.
Doing searches on cities near Delphi, university campuses, and parks, there's seems to be a few attacks where someone tries to drag a victim away.
Maybe a jogging college student was too strong for BG?
I'll bet it is hard to drag a fighting 20 year old co-ed behind some trees on a college campus because there's
a) less trees
b) campus security
c) more people milling around.
I wouldn't be surprised if BG was no match strength-wise for a healthy active, adult so he sought out a location with
a) children, teens "hanging out"
b) more forest and tree cover
c) no security personnel or cameras
I'm willing to bet here's the TYPE of crime BG might be associated with in the past, not necessarily this crime in particular:
Woman says she was grabbed and dragged by a masked man near Purdue University campus
JMO, MOO, and amateur psychological musings and relentless speculation ......