Chapel Hill, N.C. — In the 17 years since police officer Lee Sparrow took down a gunman on the streets of Chapel Hill, a lot has changed in the way that officers handle mass shootings.

"Back then, there was no training (for situations) like that," says Sparrow, who retired from the police force earlier this year.

He said officers didn't have the training or firepower to combat a massacre like the movie theater shooting in Aurora, Colo., Friday that killed 12 people and wounded nearly 60 others.

"We had 9 mm Glocks, and that was it," he said. 

But the semi-automatic pistol helped Sparrow and other officers end a shooting spree on Henderson Street in January 1995.

University of North Carolina law student Wendell Williamson, dressed in camouflage and armed with an M-1 sniper rifle and hundreds of bullets, walked down the street shooting at random. By the time Sparrow and other officers got to the scene, two men had already been killed.

A shootout between Williamson and officers followed.

"I (couldn't) believe I (was) hunkered down behind a wall, shooting at somebody in Chapel Hill, North Carolina," he said. "Finally, myself and another officer hit him in the legs."

The shootout was over in less than two minutes and Williamson was taken into custody. He was later found not guilty by reason of insanity and involuntarily committed to Dorothea Dix state psychiatric hospital.

Officers now receive extensive training to handle mass shootings, said Wake County Sheriff Donnie Harrison. In any situation, the officers' No. 1 priority is to end the violence as quickly as possible – with or without backup.

"We go after the active shooter," Harrison said. "That officer knows he has got to stop that person, because that person is still trying to kill or killing people."

Sparrow said the advancements in officer training were evident in the Colorado shooting.

"Even though I do not know (the officers involved), I am very proud of them," he said.