Lone Resource Officer Stopped Maryland School Shooting Within Seconds, Has Saved Lives Before

The school resource officer who engaged with an active shooter at a Maryland high school on Tuesday has been recognized for his "exemplary judgment" before.

Blaine Gaskill, a St. Mary's County Sheriff's Office deputy with SWAT training who had been positioned at Great Mills High School since the beginning of the school year, immediately responded after being alerted of the shooting, officials said.

Deputy Blaine Gaskill did everything he was trained to do during an active shooter situation on Tuesday, Sheriff Tim Cameron said.

"[Gaskill] pursued the shooter, engaged the shooter, fired a round at the shooter," Sheriff Tim Cameron said Tuesday, adding the deputy did everything he was supposed to do during an active shooter situation.

Gaskill contained the situation within one minute of the initial shot being fired, officials said. It's unclear if his round hit the shooter.

Maryland Gov. Larry Hogan said Gaskill is a "capable ... tough guy" who "took the right kind of action."

"I think while it's still tragic, [Gaskill] may have saved other people's lives," Hogan said.

Gaskill's interaction on Monday with the deceased gunman, 17-year-old Austin Wyatt Rollins, wasn't the first time he came face-to-face with a firearm.

In July 2016, Gaskill was responding to a complaint at a Great Mills home when a man -- identified as Pekka Robert Heinonen, 59 -- pointed a gun at him, according to Maryland newspaper The Enterprise.

Heinonen was "standing on the porch, pointing a gun at me," Gaskill wrote in a probable cause statement. "I ordered the defendant to drop the gun, at which point ... his wife walked between us. The defendant refused to comply with my demands, ... [until his wife] convinced him to drop the gun."

Gaskill, Sheriff Cameron said at the time, "used exemplary judgment" in the situation, in which "realistic, relevant and constant training obviously paid off."