Police want to know everyone Micah Johnson, the sniper who killed five officers and injured nine others, had been communicating with before the deadly shooting and are looking into weeks of phone records.
FOX 4 obtained the search warrant police are using to look for phone numbers connected to Johnson.
Investigators are searching for subscriber information, incoming and outgoing call detail records, cell tower locations, text messages, and all billing information and any transaction history going back to May 1.
Sources say Johnson drove a black Chevy SUV to downtown Dallas the night of the attack. The SUV was seen on several videos when it was parked outside of El Centro College with its emergency flashers blinking.
DART bus driver Donald Washington saw the SUV that night. He said he saw the SUV around 8:20 p.m. when it ran through a traffic light.
"When I noticed that vehicle actually proceeding on down westbound on Elm Street, it made a left turn on Lamar," Washington said. "I lost the vehicle at that point."
Police are still examining weapons, ammunition and bomb-making materials found in Johnson's home.
Sources revealed a picture of the actual gun Johnson used in the attack. It was an Izhmash-Saiga 5.45 mm high-powered rifle, a variation of an AK-style military weapon.
Johnson also had a Glock 9 mm semiautomatic pistol and a .25-caliber semiautomatic pistol, which were recovered at the crime scene. It is unknown if these guns were fired as he carried out his plan.
Sources say Johnson's mother consented to the search of their Mesquite home and her son's room. In the home, police recovered two rifles, one pound of a powder used to make explosive targets for shooting practice and a can of acetone, which can mix with other chemicals to make explosive material.
Information gleaned from Johnson's laptop led police to internet gun sites and chat rooms where he talked about weapons.