I think the perp has previous victims of sexual molestation (could be an RSO or a as yet ever caught as an adult predator).
I think the way the body was found indicates panic, which IMO indicates the perp has never killed a victim before.
But thinking of Ryan Brunn /Jorelys Rivera, she was likely his first kill (hence the sloppiness with the crime scene/disposal of her body), but after his plea deal, LE indicated that there were sealed sexual molestation complaints against him (one by a famiy member, IIRC) as a juvenile. So I think he realized if he didn't want to get caught as an adult, he'd have to not leave a victim alive.
So long story longer, it's my opinion this is a first kill, but not a first molestation/sexual assault. And I don't believe we 'know' it was a sexual assault, but with those bizarre/depraved/curious 'I just wanted to see what killing someone was like' cases, the victim isn't generally found nude/in underwear, are they?
I have read that molesters aren't necessarily into killing. Rather, they kill to cover up the crime. They have been caught before and do not want to pay the penalty, so they kill the child to conceal the evidence of the crime.
There was no trial of the killer of Somer Thompson, so we do not know what happened. Some feel she died accidentally from him being on top of her. But, I do not think the info is out there, The parents chose no trial so that there wouldn't be the possibility of him getting off.
The tarp is weird, in my estimation,
Would she fit into a large garbage bag? I am so impaired on figuring out volume. I know this sounds very cold, but to figure things out you have to detach.
Ii have large size kitchen garbage bags, I think a child could fit into one, but do not want to think too hard on this.
I may have some larger garbage bags, but not sure as hubby would be the one to use them out in the garage.
Why not put the child in a garbage bag? I may have tarps around, I have had them in the past, but they are not something I use that much.
So, why the tarp vs. the ease of a garbage bag? A garbage bag looks fine in the back of a truck.
And if thrown in water, I would think a garbage bag would be better than a tarp which is open to the elements and body parts can come off and up onto shore?