My heart goes out to him and the families of the victims.  This isn't the first time something like this has happened.  With what they can do with special effects today, why do they even have to fire a gun?  My son played with toy guns when he was little. He still got to point the gun and pull the trigger. The actors could use "fake" guns, pull the triggers, etc, and special effects can add in the sound later.  I admit, I don't know that much about guns...have never even touched a gun.  All I know is that it's too easy for someone to get hurt with a gun.  

just saw this on NBCnews.com:
"Following the tragedy, the ABC police drama “The Rookie” will no longer use “live” weapons on the show — instead using airsoft guns and adding the muzzle flashes with computers later. Airsoft guns fire plastic pellets."

It’s just awful. I can’t imagine anyone would intentionally cause this to happen.