Arizona man accused of plotting mass shooting at rap concert to spark ‘race war’

The man unknowingly detailed his plan to undercover agents, who he believed shared his racist beliefs

Arizona man indicted by a grand jury after trying to plan a mass shooting (U.S. Attorney's Office, District of Arizona)

An Arizona man was indicted by a federal grand jury after expressing a “desire to incite a race war” before the presidential election in November, authorities said.

Mark Adams Prieto, a 58-year-old Arizona-based gun show vendor, was plotting a mass shooting at a rap concert in Atlanta in mid-May, according to a complaint. His sinister plan ultimately got him indicted on charges of firearms trafficking, transfer of a firearm for use in a hate crime and possession of an unregistered firearm, the feds said.

Prieto was caught after unknowingly sharing his plans with two undercover government agents he had invited to help carry out the mass shooting, according to the complaint. Prieto allegedly entrusted them with his plan, thinking the agents shared his racist beliefs. He said he wanted the mass shooting to transpire ahead of the election because he thought “martial law will be implemented shortly after” the presidential race in November, the complaint says.

Within the last year, the agents learned that Prieto advocated for a mass shooting against “blacks, Jews, or Muslims.” Specifically, Prieto told an undercover agent that he decided to target Atlanta because “all the n****** moved” there.” He added that he decided on a rap concert because there would be a “high concentration of African Americans at the concert,” according to the complaint.

Prieto told government agents that he wanted to show “no mercy, no quarter” and called his targets “not people.” He added: “They’re monsters as far as I’m concerned.”

The attack plan was detailed, the complaint shows.

Prieto told the agents that he wanted to make clear that the massacre was racially motivated.

To accomplish that, he wanted to plant Confederate flags at the attack site and planned on shouting “whities out here killing, what’s we gonna do,” “KKK all the way” and “black lives don’t matter, white lives matter,” the feds said.

He allegedly detailed that the most important part of the mass shooting was the body count: “These people don’t belong here in this country anyway, okay.”

The gun vendor explained the timing of the attack, saying he wanted the massacre to “follow Super Tuesday so that they would know the election candidates,” the complaint says.

Prieto also stressed the importance of anonymity, advising the agents to leave behind their phones and to wear hoodies and face coverings. He also stated that he wanted all of them to carry certain weapons, including bolt-action rifles for the flanks and fast-shooting semi-automatic rifles.

He explained the choice of firearms to the agents: “You want to corral them. And some people might be trying to leave out of a corner, and you want to blast those guys. Once [they] get the idea that they are trapped then there is pandemonium. Now they’re in a panic. And they can’t get out. Now they are going to be crawling over each other to get out.”

Throughout their discussions, Prieto even sold one of the agents two weapons. When he sold a rifle to the undercover agent in March, Prieto told him to use it in the massacre, the complaint says.

Two months later, on May 15, the day the attack was supposed to take place, Prieto was arrested in New Mexico. He told the agents that he was on his way to Florida — not Atlanta.

When he was arrested, he had seven firearms in his possession and even more weapons in his home, including an unregistered short-barreled rifle.

Each conviction for firearms trafficking and transfer of firearm for use in a hate crime carries a maximum penalty of 15 years in prison, a fine of $250,000, or both. A conviction for possession of an unregistered firearm carries a maximum penalty of 10 years in prison, a fine of $250,000, or both.