 This feels familiar to a lot of shooting investigations. You have all these data points. They're gathering data points about the person, and in the middle is this question of motive, which is a blank. So what does the FBI do to try to get into that hole? Well, there are two key pieces of evidence that they have recovered that they're working on, the alleged shooter's gun and his cell phone. Both have been sent to the FBI lab in Quantico, Virginia, for analysis. Now, the FBI says the gun was purchased legally, it believes, by the shooter's father.