chief matthews verdosa said his officer's actions saved lives >> it's preliminary to go into the detailsffice to say, our officers acted heroic today. >> reporter: congressman steve scalise, the third highest ranking republican in the house, a congressional staffer, a aid and two police officer, others injuries in the scramble for safety while residents are in disbelief. >> it's echoing everywhere and then you just hear boom, boom, boom. >> you don't associate those noises with my gosh there's a shoot-out going on in the front yard >> i thought it was horrifying. >> reporter: a left this alexandria neighborhood and the nation in shock. >> we're back live now at the simpson field here in dell ray neighborhood. what you're looking at right now is a live shot of what has been going on here, a sweep by alcohol, tobacco and firearms agents who have been going up and down the length of this baseball field tonight. scoping that out, picking up shell casings, trying to identify pieces of evidence. it is not just this baseball field, which is the crime scene here, as you can see, this tape litera