Since I am not LEO the clue is somewhat eluding me,
If the gun is doing what's shown in the picture, it's a magazine problem. Specifically, a magazine spring problem. All the magazines that he mentioned are 8-rounders. At least two have the folded Devel-type follower. There's two strikes against'em from Jump Street. Seen a lotta the same trouble with those. Don't know about the other one...but it still probably doesn't have enough spring.
Now we wait for more detailed information.