My Brother Is Dangerous And Needs To Be Off The Street. How Can I Get Him Safely Committed?

Location: Oklahoma USA

I’m gravely concerned for my brother (21m) and worried there’s nothing I can do to help him.

He was recently medically separated from the army after their behavioral health people diagnosed him with schizophrenia following a major episode at some kind of field event. This not only completely crushed him but his life has fallen apart and he cannot find gainful employment and is living in govt housing. I checked up on him recently and evidently he stopped taking his medication or it’s stopped working because he’s completely lost touch with reality. Ranting and raving about how he can’t leave or talk to me because “they” will kill him and how he needs to stop “them” before it happens. That’s just when I can understand him it’s usually word salad and or crying. When we heard what happened with the military we stored his firearms at our grandparents but when I visited him he’s 3d printed his own machine gun (more knowledgable friends said it’s called an fgc9) as well as hulls for homemade mines. He didn’t tell me why and what for he just cowered in the corner and yelled for me to leave. Hes covered in what appear to be self inflicted cuts and obviously in a constant state of terror and I have to help him but afaik in the United States there is no more long term inpatient facilities he can be committed to. Which raises the main issue which is I feel I have to report him but I’m very concerned that the police will kill him or he will just get thrown in prison. Call me a coward but the reason I didn’t stay with him is even without the weaponry he is very large and still in peak physical condition and was worried he’d fly off the chain any second. the police department in our city has a reputation for being slightly trigger happy so I know something bad will happen if I contact the authorities. There has to be some other way right? I don’t think he’s completely lost all faculties or else he couldn’t make stuff like that or pretend to be normal long enough to get essentials at the store. Sorry if this was rambly I don’t know what else to do.