As investigators continue to probe for a motive in the mass shooting that left eight people dead and at least seven others wounded at a Texas outlet mall, details of the gunman's background have begun to surface, including extremist social media postings, a source tells CNN. Though authorities in Allen, Texas, have yet to publicly announce a motive for the gunman – identified by law enforcement as Mauricio Garcia – investigators are considering whether he may have been driven by right-wing extremism, a senior law enforcement source familiar with the investigation tells CNN. Garcia, 33, who was killed on the scene by an Allen police officer who was on a call nearby when the shooting started, was wearing an insignia that authorities believe may be associated with extremist groups, the source said. Investigators have also unearthed an extensive social media presence, including neo-Nazi and White supremacist-related posts and images that authorities believe Garcia shared online, according to the source. Garcia opened fire Saturday afternoon at the Allen Premium Outlets, where employees, shoppers and families with small children scrambled to take cover as he moved through the mall complex, authorities said. Among the eight killed was Christian LaCour, a 20-year-old mall security guard, whose sister Brianna Smith described him as "a sweet, caring young man who was loved greatly by our family." LaCour was "the kind of person who would just walk into the store and everyone in the room would light up because he was there," said Max Weiss, a mall store employee. The attack marks the latest in an unremitting series of mass shootings that have devastated American communities – everywhere from small towns to major cities – as they gather in schools, supermarkets, parks and other public venues that are typically deemed safe. It also comes just three days after a shooter killed one woman and wounded four others in an Atlanta medical facility and only a few weeks before Texas will mark a year since 19 children and two teachers were massacred by a gunman at Robb Elementary school in Uvalde. In addition to an AR-15 style firearm and another weapon found with Garcia, police also discovered several more weapons in his car, the law enforcement source told CNN. Neighbors of an address matching that of Garcia's parents told CNN that police and the FBI arrived at the home about an hour after the attack and had the street blocked off for several hours. Two neighbors said they were shocked and disturbed to learn Garcia was the shooter. "I know nothing happened on our block but it sends a chill down your spine knowing the suspect lives a few houses away," said neighbor Moises Carreon. Garcia had been living in some form of transient lodging, according to the law enforcement source. The Dallas Morning News reported the suspect had been staying in an extended stay hotel in Dallas. Garcia had worked for at least three security companies and had undergone hours of firearms proficiency training in recent years, according to a database maintained by the Texas Department of Public Safety. None of the companies immediately responded to requests for comment. The gunman was approved to work as a security guard in Texas from April 2016 until April 2020, when his license expired, according to his profile in the Texas Online Private Security database. As part of his work, Garcia received Level II and Level III security training. The former covers security laws in Texas; the latter, which is required for all commissioned security officers and personal protection officers in Texas, includes firearm training and the demonstration of firearm proficiency, according to Jonah Nathan, vice president of Ranger Guard, a security guard service in Texas not affiliated with Garcia's employers. Garcia also completed a separate firearms proficiency training course in 2018 which requires 6 hours of continuing education, according to the database. Private security guards in Texas undergo background checks and are disqualified if they have committed certain crimes such as assault, burglary or sexual offenses, among others, according to the Texas Department of Public Safety website and state codes. They are also disqualified if they have been dishonorably discharged from the US military; have been found incompetent by a court of law; or have been required to register as a sex offender. It's unclear why Garcia's license expired. Witness accounts, videos and photos obtained by CNN paint a vivid picture of the fear and devastation the gunman caused before he was killed by an officer who police say was already on the scene when the shooting happened. Garcia began firing in the parking lot near the mall's H&M store after he got out of his car, according to video obtained by CNN. Another witness video shows shoppers – some with small children – screaming, running and ducking behind rows of cars as the shots ring out. Steven Spainhouer rushed to the scene after receiving a call from his son, who works at the H&M and had taken shelter in a break room. When he arrived in the parking lot outside the store, he "started counting the bodies on the ground ... one, two, three, five, six, seven bodies." "The first girl I walked up to ... I felt for a pulse, pulled her head to the side, and she had no face," Spainhouer told CNN on Sunday. "I saw moms and dads covering the eyes of their kids in tears, kids holding their hands up, people running for their lives," he said. He found a surviving child whose mother had been struck and killed as she shielded him from bullets, Spainhouer told CNN affiliate KTVT. "When I rolled the mother over, he came out," Spainhouer told the affiliate. "He was covered from head to toe, like somebody had poured blood on him." As the gunman entered and made his way through the mall, shoppers yelled warnings to each other and fled as many store employees rushed to shelter customers in storage rooms or back hallways, according to several witness accounts. Weiss, the 18-year-old store employee, described hiding with coworkers and customers in a pair of rooms at the back of the store as "the most terrifying moment of my life." "I immediately reached out to both of my parents, told them I was OK," Weiss said. "But I had other things to take care of. I had to make sure that the store was OK, and that the team was OK and that the customers in there were OK." A witness in a cosmetic store at the northeast corner of the building said he watched as the shooter passed by firing his gun. Moments later, a pursuing police officer passed, rounding the corner and firing ahead of him "down range," he said. A photo obtained by CNN shows the gunman – clad in black and tactical gear – lying on the ground after being shot outside a Fatburger restaurant location in the northwest corner of the building. — CNN
