Texanon here.
Saying this one more time - that was a coyote camp. We have them all along the southern border. We hunt deer along the southern border and come across these all the time. Finding bodies is NOT unusual. Coyotes do not stop their run to bury the dead unless the family does the digging.
If you call CBP, they will come and check it out but not for very long - as the body is unlikely to have anything in USA files to verify identity, and coyotes clear out any Mexican ident.
I said this multiple times since this first broke. I hope with all the additional digging that this get put to bed now. But I am glad the Cemex thing was dug, because they are waay dirty, me having worked much for Pemex…