The man who killed seven people and injured more than 20 others in west Texas on Saturday had been fired from his job at a trucking company hours earlier, authorities say—but they're not sure what sparked the homicidal rampage. The shooting spree began when the 36-year-old suspect was pulled over for failing to signal a left turn on Interstate 20 between Midland and Odessa. "There are no definite answers as to motive or reasons at this point, but we are fairly certain that the subject did act alone," Odessa Police Chief Michael Gerke said Sunday. The chief refused to speak the suspect's name, but a police statement later identified him as Odessa resident Seth Aaron Ator. He was killed after opening fire on officers outside a movie theater in Odessa, where authorities suspect he intended to continue the killing spree.
Authorities say it's not clear where Ator got the AR-15 style rifle used in the shootings. Records show that Ator was arrested in Texas in 2001 for misdemeanor criminal trespass and evading arrest and served 24 months of probation, although this would not have prevented him from legally buying guns in the state, the AP reports. The victims in Saturday's rampage include mail carrier Mary Granados, 29. Ator shot her dead before stealing her US Postal Service truck. Leilah Hernandez, 15, was shot as she walked out of an auto dealership and Joseph Griffith, 40, was killed as he waited at a traffic light with his wife and two children. "This maniac pulled up next to him and shot him, took away his life, murdered my baby brother. Like nothing," sister Carla Byrne tells the Washington Post. "We are so broken." (A 17-month-old girl is among the injured.)