I just watched CNN.com's video report of this, and they show the pistols in evidence bags. One's most certainly a 9mm Sigma SVE. The other is some black polymer frame double-stack compact and I can't tell if it's striker or hammer fire.
The grip texture looks like it could be an HK, but I can't tell if it has a hammer or not. It could also be an XD, but there's something under the slide (locked back in the evidence bag) that looks like a hammer. (which would rule out the striker-fired XD)
Regardless, I'm thinking it was a 9mm round that didn't make it through a cell phone since Sigma's are only 9 or 40 (and this Sigma's magazine had peepholes up to round 15 and their .40 mags stop at 13...even though they hold 14.....I used to own one). And the odds that the other gun is .380 are slim cause really.....who would own a double-stack polymer pistol in .380?
They didn't show the phone.
ETA: Screenshot of mystery pistol: