BOULDER, Colo. -- A Boulder policeman who arrived a few seconds after a freshman's throat was slashed is relieved the stabbing at the University of Colorado didn't turn out worse. Master Officer John Smith said he heard screaming and saw students running away. He ran to help and faced what would be one of the more stressful situations of his three-decade career.

"It evolved very rapidly and I thought it worked out real well," said Smith.

A Boulder County sheriff's deputy, Stuart Holt, already had a gun pointed at the suspected attacker, Kenton Astin.

Smith told Holt he was next to him and started to prepare to use his Taser gun.

By his count, it's been eight or nine years since he was issued the less-lethal weapon and he was about to use it for the first time.

He said the suspect dropped the knife, but kept moving toward him, punching numbers into a cell phone, threatening to detonate something, counting down toward one.

And, he was rambling.

"'I'm the creator. I'm ... something along those lines. It's the end of the world. Columbine,'" Smith said, describing what Astin was saying.

Smith deployed the Taser but it didn't stop the suspect in his tracks.

"It distracted him enough that we were able to then close on him and take him to the ground. So it was effective," said Smith.

Several others helped the two officers get control and handcuff Astin.

A day later, Smith realizes that, considering where the suspect was, it would have been a different story if he had used a gun to take him down. Astin was standing at the top of a flight of stairs, in front of the busy University Memorial Center building, with students all around.

"You know, my daughter is a college student. So those things come into play as well," Smith said.

He won't look for accolades but he's glad no shots were fired.

"Well, it makes you feel great. You know, we always want to be in a position to stop things before, you know, they get worse," Smith said. "This is our job. This is what we're out there to do. And if we're called on to do it and have the opportunity to be in the right place at the right time, that's just what we're going to do."