Have regular and irregular patrols of MPs and make sure carefully selected officers (No *Mohammad* types) carry sidearms at all times.
This clown wouldn't have gotten far.
The people in the military presently carrying sidearms, except base LEOs, are those who "don't really need them" (officers), or those who should be carrying some type of more capable weapon (security).
The rest should have the ability to secure at least their own safety or better, to use a sidearm as intended, to "fight their way back to the rifle they shouldn't have set down."
The elitist idea that rank and file military cant be trusted with a pistol is asinine. This idea was born from the tradition of sword and pistol representing status of a noble in command and has no place in a functional modern military.
If Im supposed to trust an individual to drive a tank, fire artillery, fly ordinance over my city, or protect my Secrets, then I can trust them to carry a sidearm.
Those who cant be trusted SHOULDNT BE IN THE MILITARY and need to be booted.
* Obviously, I don’t mean that those engaging in specific tasks where the sidearm is more likely to do harm should be carrying while doing those specific tasks, ie the lab tech doing MRIs shouldn’t be carrying while in the same room as the imager, etc.