prince william county police lieutenant carlos robles was offduty when the call for shooting and gunman on the loose went out in woodbridge. he shares his story in his cloous inthis exclusive interview. minutes before the call, eric smith shot and killed retired atf agent, gregory holly, stealing his ipod and badge. holly was walk his dog near his house when it happened. lieutenant robles happened to be a couple blocks away in his car. >> the homicide suspect made it across the road. >> after the shooting, police say smith ran across cardinal drive to this fence right here. he tried to jump it but wasn't able to. then say they he crawled under here. robles saw him in a cul-de-sac on the other side of this fence. >> a good suspect. he had the demeanor. he was out of breath. matched the description. >> reporter: at that point the lieutenant chased him and tackled him. holly's family and friend thank him. >> you say this officer is a hero. why? >> he took a killer off the street. and police recovered holly's ipod, and other belongings. and they also found the suspect's gun. tonight that su

prince william county police lieutenant carlos robles was off duty when he heard an agent had been shot and killed near his home. when he spotted suspect eric smith he tackled him right on the sidewalk. he spoke exclusively to news4. >> the fact that i was able to contribute and all the officers there were able to contribute and help with arresting this individual the same night that it occurred, it speaks volumes for our department. i'm just part of the team. i'm not a hero. if it wasn't me, you know, it was somebody else. >> police have recovered an ipod that they say smith stole during the shooting. smith now faces first-degree murder charges. >>> people around the country will pause for a moment of silence a little more than a half hour from now to mark the 20th anniversary of the first attack on the world trade center. six people were killed and more than 1,000 others injured when a truck exploded below the north tower. six islamic extremists were later convicted of that attack. the moment of silence will begin at 12:18. that's when the bomb went off. >>> today also marks one year