LITTLETON, Colo. -- For the first time, the public is getting to hear the voice of a gunman who held six students hostage, who killed one girl before killing himself, and who shattered the sense of security of a small mountain town.

On Friday, Littleton police released an audio tape of a threat Duane Morrison made to the employees at Rocky Mountain Harley Davidson shop in November 2004.

In the tape, Morrison threatened to kill them and used derogatory terms to address dealership employees, who he'd accused of mailing an unwanted catalog to him. He didn't want the catalog because he was still upset over lack of service he allegedly received after purchasing a motorcycle from them.

"Hey, Duane Morrison here," the tape begins. "I just wonder if you f****** are responsible for sending this to me. I'd sure like to get this stopped. I guess my last threat down there didn't carry very far."

"What do you think it will take to get this stopped? Uh, maybe a visit with an assault rifle? Um... Damn, I sure hate for it to come to that. Maybe we can get something stopped before then," Morrison said. "What do you (expletive) think? Why don't you get in touch with me and let me know. Later, (expletive)."

Morrison had bought his motorcycle in 2002. Nearly two years later, he purchased an alarm and some new pipes from Rocky Mountain Harley that he claimed were damaged or didn't work.

"Anytime someone makes reference to using an assault rifle in coming down to a business and getting their attention, or something to that effect, that certainly raises a heightened awareness for us," said Littleton Police Sgt. Sean Dugan.

Littleton police said it's not unusual for irate customers to make threats but this threat went beyond the usual. That's whey they issued the arrest warrant for harassment.

"I don't think anyone could have drawn from a message like that that he could do what he did the other day -- to show up at a school and take children hostage and harm children and kill a child. That wasn't what this was about. This was about an angry customer. That happens a lot -- telephone threats are made, people are unhappy with levels of service," Dugan said.

Lakewood police arrested Duane Morrison July 11, 2006 on a warrant out of Littleton. Making a threatening phone call is a misdemeanor offense.

Morrison bonded out, showed up to a Littleton court in August and was sentenced to nine days. That sentence was suspended because he had no other violations in a 12-month period.

"We feel we did everything we could," Dugan said.