Police are out of control....

A man killed an alleged intruder. Then police showed up and killed him.

Alex Horton

The flurry of 911 calls went out to the Aurora Police Department early Monday, advising authorities that there was something wrong on a tree-lined street in the Colorado city.

One call was very specific and dire: A woman said an intruder was breaking into her home in the middle of the night.

Officers arrived on scene and heard muffled gunshots from inside the home, sparking bedlam in the east Denver suburb.

Police encountered a man with a gun. The officer shot him, authorities later said in a statement.

Officers then fanned out inside the house searching room to room for any other possible suspects or victims. They discovered a man sprawled on a bathroom floor, shot dead.

At some point, the officers came to a grim realization.

The man in the bathroom was the alleged intruder, who was killed by the man police had just fatally shot in what Police Chief Nick Metz called a "very chaotic and violent" incident.

Authorities have yet to release the names of the men, pending next of kin notifications, Metz said Monday, adding the involved officer was reassigned to other duties with pay.

The intruder seriously injured a child in the home, but the injuries were not life-threatening, Metz said.

A neighbor, Brad Maestas, told the Denver Post he heard the initial gunshots and armed himself until he saw police swarm nearby. He watched paramedics take away the victim on a gurney.

"He was a family man - a grandpa that was protecting his family," Maestas told the paper, which also did not identify the man. "It's messed up."

The Denver Police Department is assisting with the investigation, Aurora police spokesperson Kenneth Forrest told The Washington Post on Tuesday.

Findings will be turned over to the 17th Judicial District Attorney's Office, which will determine if any criminal charges will be filed against any involved person, the office said in a release.

Forrest declined to address questions, citing the district attorney's request to withhold facts as the investigation continues.

Many details remain unclear. The department did not say if the victim was killed by police inside or outside his home, or if he tried to identify himself as a resident before police shot him.

Aurora police also did not say if the victim was handcuffed or provided medical aid before he was taken to a hospital, where he later died. It was also not clear how long it took officers to determine they had killed the wrong person.

"This is a very heartbreaking and tragic situation for everyone involved. We are providing assistance through our victim advocates to help the family of the deceased resident through this very difficult time," Metz said.

The incident marks the second officer-involved killing in as many days in Aurora. A man driving a stolen truck was shot dead after he rammed several police cruisers, the Denver Post reported.

In 2012, a gunman entered an Aurora movie theater and killed 12 people, perhaps its most notable event. Since then, the city has been eager to demonstrate the town as a secure place to raise a family.

The police department voice mail ends with an appeal: "Thank you for calling the city of Aurora, the safest large city in Colorado."