Pete Arredondo was elected to the City Council in Uvalde, Texas, a few weeks before the May 24 shooting that killed 19 children and two teachers, plunging the small town into grief.
Arredondo told the Uvalde Leader-News he was stepping down so local officials can "move forward without distractions."
A top state law enforcement official said last month that Arredondo, the onsite commander during the shooting, made "terrible decisions" and officers at the scene lacked sufficient training, costing valuable time during which lives might have been saved.
Uvalde's government said in a statement that for Arredondo, resigning would be "the right thing to do," but that city officials have not heard from Arredondo directly about his plans. Arredondo has said he never considered himself incident commander and that he did not order police to hold back on breaching the building.
Outrage over the massacre helped galvanize support in the U.S. Congress for the first major federal gun reform in nearly three decades, which President Joe Biden, a Democrat, signed into law on June 25.
Before announcing his plans to resign from his City Council seat, Arredondo was already at risk of being removed from office after missing several council meetings. The city's school district last month placed him on administrative leave from his duties as police chief.
Many parents and relatives of children and staff at Robb Elementary School have expressed anger over delays in police action after the gunman entered the school.
As many as 19 officers waited for more than an hour in a hallway before a U.S. Border Patrol-led tactical team finally made entry and killed the 18-year-old gunman.
A state official said last month that police wasted time searching for a key to the classroom where the shooting occurred, but that the door that needed opening was not locked.
(Reporting by Jason Lange; editing by Jonathan Oatis)
