Federal agents entered school 30 minutes after arriving in Uvalde, per an NBC News report

The federal agents decided to confront the gunman, disregarding local police who told them not to enter Robb Elementary School, NBC News reported.

• Federal agents were told by local police not to enter Robb Elementary School, NBC News reported.
• After about 30 minutes, the agents decided to ignore the instruction.
• NBC News cited two senior federal law enforcement officials.

Disregarding instructions from local police, federal agents decided to enter Robb Elementary School about a half-hour after arriving from the border, ultimately killing the gunman who had murdered 21 people inside, NBC News reported.

The agents from the tactical unit of US Customs and Border Protection waited 30 minutes before choosing "of their own volition," per NBC News, to lead a group of officers inside the building, according to the report, which cited two senior federal law enforcement officials. The agents had initially been told not to enter the school by local police.

Texas law enforcement officials have repeatedly changed their version of events, initially claiming that the 18-year-old gunman had been confronted prior to entering the school.

Earlier on Friday, Steven McCraw, director of the Texas Department of Public Safety, told reporters that in fact the chief of police for the Uvalde Consolidated Independent School District, had ordered officers not to confront the gunman, apparently believing that he had barricaded himself and was no longer an active threat — despite children inside the school calling 911 and pleading for assistance.

BORTAC and UCISD Police Department were not immediately available for comment.

This is a developing story. Check back for updates.