not exactly boy scouts, said ohlson. >> well, the police asked these people if they had guns.k page displaying both a gun and a knife. >> reporter: and they must have had a gun that night, said ohlson, because on the route of the chase, investigators found three shell casings, casings that did not match any of chad's guns. >> the interesting thing, though, is he said, "they shot at me three times." and they found the three .380 casings that were together, that were not from chad's gun, corresponding with the three shots. >> reporter: and there was another, truly stunning clue, collected on the night of the shooting, said ohlson. according to his forensic expert, there was gun residue inside the young men's car and even on some of their hands. >> somebody shot out of that car. >> reporter: because? >> because of the gunshot residue in the car, the lack of bullet strikes on that side of the car and the gunshot residue on the hand of the person who was riding shotgun, if you will. >> reporter: and why did chad keep shooting at the car after it made a u- turn? very good reason, sa