The typical mid-afternoon calm was shattered in a Highlands Ranch neighborhood by gunshots and shouts of "get back inside."

Law enforcement would soon converge on Castle Ridge Circle, a nearby school would be placed on lockout status and a Code Red notification would be sent to residents within a half-mile of the street, telling them to shelter in place.

A 2 1/2-hour standoff with law enforcement ensued Sept. 24, coming to an end when SWAT officers found the suspected gunman, Ryan Lane, dead.

Lane, 36, reportedly had fired shots at a resident of one of the homes on Castle Ridge Circle. That man escaped unharmed, fleeing to a neighor's house, according to a Douglas County Sheriff's Office spokeswoman.

Lane, who went inside the home after the confrontation with the resident, apparently died of self-inflicted injuries, the spokeswoman said.

About 24 hours later, everything looked almost normal in the neighborhood. The only visible marks of the previous day's events were bullet holes in the home in the 9800 block where the shooting took place and a surplus of cars slowly driving by it.

Area residents said no one would have expected such a violent incident, especially in this neighborhood.

Shots fired

Shortly before 3:30 p.m. Sept. 24, one resident of the neighborhood had just walked out of her front door and was headed to pick up her son from kindergarten at Trailblazer Elementary. The 33-year-old woman, who requested that her name not be used, said she heard a neighbor shouting, telling her to “get back inside.”

She hurried into her house and spent the next couple hours in her basement as SWAT teams, drones and sheriff's deputies swarmed the neighborhood, she said the next day.

Reports of shots fired came in to the sheriff's office at 3:21 p.m. About a block away, Trailblazer Elementary was preparing to release students for the day. The school, however, was put on lockout status as SWAT teams and deputies surrounded the nearby home and blocked off Castle Ridge Circle.

Video recorded by a resident from across the street shows SWAT teams attempting to contact Lane using a megaphone.

When they didn't get a response by about 6 p.m., SWAT officers used "diversionary grenades" to create an intense, distracting noise, then sent a robot in to investigate the house and eventually entered.

Inside, they found Lane dead, along with at least one gun, said Deputy Lauren Lekander, a spokeswoman with the sheriff's office. He appeared to have taken his own life, she said. Deputies did not fire any weapons during the incident and did not hear gunshots after surrounding the home, she said.

Lane and the intended victim knew each other and may have been friends, but a motive for the incident is not yet clear, Lekander said.

No other fatalities or injuries were reported from the incident. The coroner's office is expected to have the official cause and manner of Lane's death in about four to five weeks.

A reminder of STEM

“You always learn something from every situation, but after STEM we learned more,” Undersheriff Holly Nicholson-Kluth said the night of Sept. 24 at a Highlands Ranch Metro District board meeting. “We're trying to really work together toward making things seamless when we hit incidents like this.”

The undersheriff wasn't the only one recalling the May 7 STEM Highlands Ranch school shooting the day of the standoff.

Jason Link lives nearby and has a child who attends Trailblazer, which is about 2 1/2 miles from STEM School.

"I'm concerned about it given all the things that have happened in the past six months,” Link said while parked down the street from the school, waiting for word of when the lockout would end and he could take his child home. “You pull up in the parking lot and see all the police in the parking lot and think 'not again.'"

The woman who was barricaded in her basement also thought of the school shooting, which left one student dead and eight injured, she said.

“It's very scary," she said, "especially when your kids are at schools and you don't know what's going on."