Why not stand up military police units that would be trained and full time? This is already a thing. I used to eat breakfast with them during their training r

Why not stand up military police units that would be trained and full time? This is already a thing. I used to eat breakfast with them during their training routines. They were all active duty military Army but they were wearing police uniforms from all around the state with high rank and high tenure on their sleeves. They are all trained in law enforcement.