[Travis McGee]

This is the unusual carbine/SMG the 5.7X28 caliber was created for. It's called the FN P-90. It's for Secret Service and other bodyguard and security details. The caliber with AP bullets is designed to defeat body armor. The unusual magazine fits on top, and the bullets are rotated 90* to feed.

The pistol the killer used was created as an afterthought, to give elite security guards a handgun that uses the same kevlar-defeating caliber.

I don't know what kind of ammo the killer used. The AP ammo is supposedly not available to civilians.

[Vendome]

maybe I should get one.

[LiveFree99]

Last year I took a carbine course with a guy who used the 5.7x28 carbine. He was getting good accuracy out to 200 and 300 yards but the little rounds weren’t doing much against the reactive steel targets, even at close range. He complained that the trigger was spongy, though.