A man accused of gunning down people at a busy Walmart in El Paso last month was indicted Thursday for capital murder, prosecutors announced.

Patrick Crusius, 21, of Allen, Texas, was indicted in connection with the Aug. 3 mass shooting that left 22 dead, District Attorney Jaime Esparza said. El Paso prosecutors are seeking the death penalty for Crusius, who remains jailed without bond.

Crusius' defense lawyers did not immediately respond to requests for comment. Attorney Mark Stevens previously said he will use "every legal tool available" to prevent Crusius from being executed.

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Prosecutors have said Crusius surrendered to police after the attack saying, "I'm the shooter," and that he was targeting Mexicans. In court documents, prosecutors alleged that Crusius was the author of a screed published shortly before the shooting that said it was "in response to the Hispanic invasion of Texas."

Survivors of the El Paso attack have held vigils around the city, including outside of the jail in downtown El Paso where Crusius has been kept isolated from other prisoners, on suicide watch.

The case has fueled anger among gun control and immigration advocates, and caused political blowback.

Texas Gov. Greg Abbott acknowledged weeks after the attack that "mistakes were made " when he sent a fundraising mailer encouraging supporters to "take matters into our own hands" and "DEFEND" Texas. Abbott has pledged to invest in a domestic terrorism taskforce and has suggested he would support an expansion of firearm background checks. He has resisted calls to regulate the sale of military-style rifles like the one authorities say Crusius used in El Paso.

Texas Lt. Gov. Dan Patrick drew the ire of the NRA last week after expressed support for background checks.

authorities say Crusius used in El Paso.

Patrick Crusius mugshot
Mugshot of Patrick Crusius, 21, who is charged with capital murder for the El Paso mass shooting on August 3, 201.
FBI