An emergency call placed moments before Saturday’s shooting rampage in Colorado Springs has sparked intense debate on how police should respond to armed people in public given Colorado’s open carry law.

Naomi Bettis told The Denver Post she called 911 after spotting her neighbor, 33-year-old Noah Harpham, armed with a rifle on the street. She says a dispatcher explained Colorado allows public handling of firearms.

Harpham went on to kill three people.

The open carry law has become a central focus in the tragedy after scores across the country took to social media to question the Colorado Springs police department’s apparent lack of immediate response to Bettis’ report.

Police agencies statewide say the statute poses a difficult question of how to react when citizens call — frequently — to report an armed person in public. Is it an emergency or not?

“A lot of (our reaction) depends on information we obtain from the person calling in,” said Julie Brooks, spokeswoman for the Arapahoe County Sheriff’s Office. “The information we get from the caller is vitally important.”

AUDIO: Hear raw audio from Colorado Springs police as they responded to the shooting

Colorado Springs police have yet to speak at length about their response before and during the rampage, including whether or not officers were dispatched following Bettis’ initial call.

“He could have shot me,” Bettis said, adding she was perturbed by the dispatcher’s reaction and feels prompt action could have prevented catastrophe.

Harpham killed bicyclist Andrew Alan Myers, 35; Jennifer Michelle Vasquez, 42, and Christina Rose Baccus-Gallela, 34, during his spree before dying in a shootout with officers.

Myers’ grandfather said Tuesday his grandson was a father of two who spent a decade in the Army, including three tours in Iraq. Witnesses said Myers pleaded for his life — yelling “Don’t shoot me! Don’t shoot me!” — before being killed.

Denver-area law enforcement agencies say their response to armed people in public varies on the circumstances.

“Is this person exercising their rights or about to start a very serious situation in which someone is going to be killed?” said Jacki Kelley, spokeswoman for the Jefferson County Sheriff’s Office. “We just don’t know the difference.”

Kelley said deputies, for instance, respond with lights and sirens blaring when an open carry situation is reported outside a school. Recently, the sheriff’s office has twice fielded reports from alarmed citizens when someone had a gun in a movie theater.

In those situations, deputies made an emergency, immediate response.

“That can be sensitive because of the Aurora theater shooting,” Kelley said.

In Denver, police say they always respond to reports of a person openly carrying a firearm because doing so is banned in the city.

The topic of open carry is highly debated between those on both sides of the gun control issue. Scores of videos posted online show confrontations by open carriers and police, including people who are stopped with guns outside schools and businesses.

An 18-year-old in Aurora generated buzz last year when he posted a video on YouTube showing one of those encounters with officers after being spotted carrying a shotgun down the street.

“It’s not a crime,” an officer tells the teen, “but you’re causing alarm to people.”

MORE: Colorado Springs shooter made incoherent online posts before rampage

Dan Montgomery, who served for 47 years as a police officer, including 25 years as Westminster’s chief, said he feels police in Colorado Springs should have rushed to the neighborhood after Bettis’ initial report on Harpham.

“That is just too suspicious,” Montgomery said of the situation.

Having police respond with lights and sirens can also alert people in the vicinity to a potentially dire situation, he said.

“If you’ve got someone walking down the street and they are holding a rifle in their hands, that requires an emergency response by police,” said Montgomery, who now runs Professional Police and Public Safety Consulting . “What the hell are they doing with the rifle?”

Jesse Paul: 303-954-1733, jpaul@denverpost.com or @JesseAPaul