Officer Eddie Thornton of the United States Capitol Police, while off duty, returned fire on an unstable gunman to prevent him from harming other people. For his actions, Thornton has been named December 2010 Officer of the Month by the National Law Enforcement Officers Memorial Fund.

Thornton had just finished his shift and changed into street clothes when he stopped by to visit with his mother on the night of July 16, 2009. She was just leaving work at a daycare center in an apartment complex. As the two stood talking in the parking lot, Thornton's mother mentioned she had heard a gunshot minutes before. Thornton guessed his mom had just heard a kid setting off a firecracker left over from the Fourth of July. He'd soon find out he was wrong.

A few minutes into their conversation, a man walked hurriedly from the apartment building holding a cell phone. He said he was going to call the police because his neighbor was firing a gun.

"I told my mom to get in her car and get out of the neighborhood because I didn't want her to get involved in anything," says Thornton.

As mother and son walked back to their vehicles, Thornton saw a man wearing a police officer's duty belt and a blue multi-pocketed vest. "I thought he was an officer and maybe he'd misfired a weapon in his house," Thornton remembers.

But as the officer got into his Dodge Ram truck, the man with the duty belt started firing on his vehicle. Thornton lay down along the front seat as glass from his truck's windows shattered around him. He kept peering up to check the assailant's location.

"The only thing I could think at the time was I wanted to survive and get out the vehicle, but I knew my mother was two or three cars away from me," says Thornton. "I didn't want him to make it to her and the other people there."

When he saw the gunman walk past his truck toward his mother's van and a nearby playground, Thornton jumped out of his vehicle. The man shot at Thornton and the officer shot back. A gun battle ensued in the parking lot.

At one point, Thornton was sure he had hit the man, who then turned to walk behind a car. Thornton took that pause to return to his truck and put another magazine into his weapon and pursue the gunman. It was then that the Prince George's County (Md.) Police Department arrived on the scene, responding to 911 calls. Thornton gave them a description of the man, whom they found lying on the ground next to the vehicle where the officer had last seen him.

It wasn't until a bystander noticed blood on Thornton's shirt that he realized he'd been shot in the back. He believes it happened when he was in his truck, and adrenaline kept him from noticing the pain. Thornton fully recovered from his gunshot wounds and is back on the job. A bullet went through the van belonging to Thornton's mother, but she was unharmed.

The gunman survived his extensive injuries, but he did face consequences for his actions. It was discovered he'd had a dispute with his roommate, a military police officer. When the officer left the apartment, the man took his roommate's gun and exited the building, shooting.

The man, a Senegalese national, had paranoid schizophrenia and hadn't been taking his medication. Although he was not found criminally liable for his actions because of his mental condition, he was deported.

"I feel like God places us in places and situations for a reason, and me being there provided the opportunity to stop a man from shooting at or hurting many innocent people," says Thornton. "I was just in the right place at the right time. Thankfully my actions were the right ones at that time."

For his ability to react appropriately, Thornton gives credit to everyone who has ever provided him with training, including his agency, which he believes is underappreciated. "Although it's an award I'm receiving, I look at it as an award for the United States Capitol Police," he says.

Thornton is also especially grateful for the support fellow officers gave him and his entire family. Law enforcement officers of all ranks checked in with them regularly. Officers who had been in similar situations convinced Thornton to talk to a professional about his feelings following the incident, and made him understand that it's OK to do so. He's glad he listened to their advice.

"At work when you're dealing with the chief and inspectors you know their position and you know what you need to do, but in this situation they were there as friends, and I definitely appreciate that," says Thornton. "And to any other officer I would say, know that you can trust anyone wearing blue when you're going through something like this. They're all looking out for you."