By the way Welcome to Free Republic
It appears that toxicology tests on Riehl’s body would be expected. From what was published about his work history, he was recently affected by something.
It turns out that he was a medic in the Army. There’s a pretty good chance that he was the general hospital unit type (main post, not on patrols). In the videos, I saw rantings from the mind of someone most likely affected by drugs. Most mentally ill people have abused drugs for years.