Five officers with Texas’ Department of Public Safety are under investigation for their actions during the May 24 mass shooting at Robb Elementary School in Uvalde, Texas, the Austin-American Statesman reports. The officers have been referred to the state’s inspector general’s office, which will determine if they violated any policies or their training. The tragedy that claimed 21 lives heralded intense backlash against state and federal law enforcement for their 77-minute delay in confronting the shooter. By the time the gunman was killed, 376 officers were at the scene, 91 of them DPS troopers. DPS head Steve McCraw called the response an “abject failure,” and said officers wrongly treated the situation as a barricaded subject rather than an active shooter. “DPS Officers responding to an active shooter at a school will be authorized to overcome any delay to neutralizing an attacker,” McCraw wrote in an internal July email to staff. “When a subject fires a weapon at a school he remains an active shooter until he is neutralized and is not to be treated as a ‘barricaded subject.’”