So, what do you think he's packing under that vest? I noticed his Blackberry is on his left side, so that leaves lots of room on the right. No visible lump, but then if the Blackberry doesn't make a lump, the vest clearly has enough body to hide a pretty bulky object.

EDIT TO ADD: the vest does appear to have the tighter-than-normal cut armholes to hide a shoulder holster, but I'm guessing it wouldn't be buttoned if he had one under it.