where i got it from? well sir, i actually watched some speeches on youtube by a guy who wrote a book about the subject called devil's highway, he went out on some patrols with border agents and one asked him why would the person be naked, the author said "because he lost his mind" and the agent said no, it was because of the desert effects on a person. It's all on youtube if you want to go watch it.
as far as elisa, i have a hard time believing that she was attacked or forced anywhere because she had no marks on her body except some on her knees which probably came from climbing up to get into the tower. Unless there was some kind of coverrup, the findings of her autopsy give no indication of rape, violence or anything else. Also, i find it odd that the water was tested and was found to not have anything detectable in it, that's hard to believe especially (forgive me for mentioning) part of her intestines had come out of her body. also, the issue of missing footage, some people say it's because the camera turns off without motion, automatically, someone else has said that it's also possible that someone else was in the footage who wasn't connected with the case and the police removed it to protect their anonymity.