content: My guess is 9mm, or possibly .40 based on the 2 unspent rounds near the broken mag, .45 rounds have the half-sphere look the bullet. The shells nearer the bottom to appear to be bigger, but its really hard to tell with this really weird low-def picture. The mag appears to be S&W, but again, hard to tell. Theres a video of the assassination with the guy waving around the gun in question, bu its pretty hard to make out: https://www.youtube.com/watch?v=TCJRnynAon0