Allen, Texas - Mauricio Garcia, the gunman who killed eight people and wounded seven more at a mall in Allen, Texas, had "neo-Nazi ideations," authorities revealed on Tuesday.

Disturbing new details have emerged about the 33-year-old shooter who opened fire at the Allen Premium Outlets on Saturday, killing a security guard, two elementary school-aged sisters, and a couple along with their three-year-old son.

While investigators still don't know why Garcia committed the heinous act of violence, authorities at a Tuesday afternoon press conference said he had done research into when the mall was busiest and posted images to social media of a store near to where he began his murderous rampage.

Hank Silbey, regional director of the Texas Department of Public Safety, noted that Garcia had three guns on his person and five more in his car – all of which he had purchased legally.

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Garcia did not have a known criminal record and was "not on the radar of police at all," Silbey said.

Nevertheless, the shooter had clear "neo-Nazi ideations," as illustrated by the swastika and SS tattoos on his body and an RWSD (meaning Right Wing Death Squad) patch on his clothing.

Garcia was discharged from the US Army in 2008 and sent to boot camp for mental health concerns. He received an "uncharacterized" discharge, often given to recruits who don't make it through training or the first 180 days of enlistment.

Police shot and killed Garcia on the scene. They have taken possession of his computer and phone as the investigation continues.