Cody Briseno, a funeral attendant who works across the street from the site of the state's deadliest school shooting, was one of the first people to encounter the gunman on May 24.
Briseno had rushed to help after the shooter's pickup crashed outside Robb Elementary School, but fled after seeing the 18-year-old with an "evil look" holding a rifle.
In an exclusive interview with NBC News, Briseno, who has helped bury several of the victims, including a relative, described the encounter and how he was prepared to charge the shooter after his wife brought him his gun, but was told by arriving officers to back away.
"Hey, what are you doing," an officer asked as Briseno began to march toward the school, he said. He recalls responding, "I'm going to go in and try to stop them."
“I told him that he’s already inside the school,” Briseno said. He said the officer told him to stay back and shut up.
Briseno did not want to say which department employs the officer.
Read the full story on NBCNews.com.