, about 5:41 p.m. , killed Jorge Lopez . Garland police said Lopez , 20 , was sitting in his Nissan at a traffic light when a man in a pickup pulled alongside him and fired shots into his car , killing him . A few minutes after the Garland shooting and two miles away on LBJ Freeway , a gunman fired at two tractor-trailers . While one driver escaped injuries , William Scott Miller , 42 , of Frankfort , Kentucky , was shot to death behind the wheel of a United Van Lines truck , police said . `` He was going to be traveling home , '' Craig Miller said . `` He was about to park his rig . He was going to get on a plane to fly to be with his wife and children for the Christmas season and then come back to this location . '' Miller called the truck driver a hero , saying he was able to control his rig before he died -- preventing other motorists from being hurt . The fourth attack came a mile west on LBJ Freeway when gunfire shattered the windshield of another tractor-trailer . The
-LRB- CNN -RRB- -- A former Utah policeman is a suspect in at least three of Monday 's four rush-hour shootings near Dallas , Texas , including one of two fatal attacks , police said Tuesday . CNN affiliate KSL in Salt Lake City , Utah , provided this file photo of the Dallas suspect , Brian Smith . The suspect , Brian Smith , tried to commit suicide after the Monday-evening shootings and was in a hospital in serious condition , Dallas police detective Lt. Craig Miller said . Police used ballistic tests to link Smith , a Utah state police officer for 12 years , to the shootings in which one driver was killed , one was injured by shattered glass and one escaped uninjured , Dallas police detective Lt. Craig Miller said . Miller said it is unclear if Smith was involved in the other fatal shooting , which was the first attack of the evening . Four motorists were attacked along a three-mile stretch near and on the LBJ Freeway , about 10 miles northeast of downtown Dallas , on Monday evening , police said . The first attack , which happened in Garland , Texas