So, back on topic. When I first got into law enforcement in the 70s, M1carbines we VERY popular. In the 1980s, I carried one as a trunk weapon before I got my Sterling AR180, then went back to the Carbine after I foolishly sold the 180 since it was NOT an AR15 (how stupid was that. I now realize the Ar180 is a better weapon than the AR15). For much of the time until retiring around 2000, the M1 carbine was my go-to gun.
There were a number of other officers that also used M1 carbines. They were actually more popular than the Mini-14s, which at the time had dismal accuracy compared to my carbine. One Sgt. had an Alpine, and another deputy had a National Ordnance. I had an Underwood at that time.