In the two months since Halloween, there has been an average of at least one shooting involving a Colorado police officer every 3½ days.

The 15 encounters during that span have left eight suspects — all of them men — dead, according to a Denver Post analysis. One officer was killed in the shootings, and eight others wounded.

Authorities say that although they cannot pinpoint a reason for the rash of gunfire involving law enforcement, each incident has taken a major toll, leaving officers on temporary leave and prompting time-consuming investigations.

In Colorado Springs, several young members of the police force have simply quit under the stress. In Aurora, where the latest shooting left an auto theft suspect dead Monday night, commanders are scratching their heads trying to determine what is behind the trend.

“I wish I knew. Because if I knew why, I would be able to do something about it,” Deputy Chief Paul O’Keefe of the Aurora Police Department said at a news conference Tuesday. “We don’t control (the) actions of other folks.”

Aurora police have been involved in more shootings since Halloween than any other agency in the state, killing three men and accidentally wounding a fourth when an officer slipped on ice and fired unintentionally.

“Whenever an officer is involved in a shooting, it is a critical incident,” said Sgt. Chris Amsler of Aurora police. “It’s not something we take lightly.”

Amsler said officers have been even more vigilant in the wake of the shootings, adding that police are trying to be more aware of their safety and surroundings to prevent future incidents.

“They are taking every precaution they can when they are out on the street,” he added.

Six officers from Aurora’s force remain on leave as the incidents are investigated. Officials say some teams have been left short-handed and that supervisors have shuffled the staff to fill gaps.

This all comes on the heels of a national conversation in the past year about police shootings that has left officers around the country feeling targeted. Of the 15 incidents since Halloween, six of the suspects shot at police, and three others pointed a gun at officers before being killed. Another suspect hit an officer on the head with a meat cleaver before stealing a patrol car.

“Some toll”

Colorado Springs has seen the most high-profile police shootings in the past eight weeks, including the Halloween killing of 33-year-old Noah Harpham after he gunned down three people in an apparently random rampage. Then the Nov. 27 attack on a Planned Parenthood clinic thrust the El Paso County city into the international spotlight.

In the immediate aftermath of the Planned Parenthood shootings, so many officers were involved and placed on leave that a Douglas County SWAT team was put on call to help out.

“We’ve done a whole crisis recovery for the department for all of our employees, both civilian and sworn,” said Lt. Catherine Buckley, Colorado Springs police spokeswoman.

Buckley, who has been an officer in Colorado Springs for 22 years, said she can’t remember another time in which so many police shootings took place.

“It has had some toll,” she added.

The Denver district attorney’s office has investigated 13 officer-involved shootings in the city this year, more than any other year since 2000, The Post found.

The second-highest number of annual officer-involved shootings in the past 16 years was 10 in 2007 and 2003, according to a city prosecutors’ list of officer-involved shootings.

The shootings in Denver this month include the wounding of police Technician John Ruddy, who was shot in the leg Dec. 2 in a gunbattle that left a wanted man dead.

Six days later, Officer Tony Lopez Jr. was wounded critically in a shootout with a suspect during a traffic stop. Lopez underwent several surgeries, and authorities credited the actions of first responders with saving his life.

“It’s the worst feeling in the world,” Lopez’s sister, Meghan, said at a news conference of learning her brother had been shot. “Your stomach sinks. You go into shock, and you don’t know what to do.”

A strain

Outside of departmental issues, officer-involved shootings often complicate law enforcement’s relationship with the public, said Seth Stoughton, an assistant professor of law at the University of South Carolina who studies policing. Even when use of deadly force is justified, he said, people want answers.

“Even in the best of situations, a police shooting can strain the relationship between an agency and the public,” Stoughton, a former officer, said. “And it strains it from both sides.”

Stoughton explained that the public might lose trust in their officers and the officers in turn might begin to feel like the public does not understand the complicated facets of their work.

Evans Police Chief Rick Brandt, who serves as head of the Colorado Association of Chiefs of Police, said members of his organization have not been discussing the rash of shootings. He added that they haven’t stood out among other times during his tenure.

“There’s been no conversation about it,” he said. “Not even e-mails.”

But within the agencies involved, effects can ripple and be widespread, said Jefferson County Sheriff Jeff Shrader. He added that in his experience, officers involved in shootings are each affected differently and that those impacts are often transferred onto colleagues.

“That being said, I haven’t run into any (officer) that hasn’t been affected in a deep and profound way.”

One of Shrader’s deputies on Dec. 11 shot and critically wounded 38-year-old Michael Manaois, whom authorities were trying to apprehend inside the Governor’s Plaza Shoes & Service store at 9880 W. Belleview Ave.

Officials said Manaois bolted out a back door into an alley and pointed a handgun at a deputy, who then opened fire. The deputy remains on leave as prosecutors investigate the case.

“It’s something you have to come to grips with when you come into the business,” Shrader said of using deadly force on the job. “You had to use that force likely because someone was trying to cause serious bodily harm to you. You have to reason through that.”

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

Staff writer Noelle Phillips contributed to this report.

Recent officer-involved shootings

Dec. 21: Aurora police shot and killed a man driving a stolen Jeep at a Denver convenience store after he used the vehicle to threaten police and customers.

Dec. 19-20: A 43-year-old Penrose man fired shots at officers during two police chases.

Dec. 19: A bulletproof vest saved a Northglenn police officer who was shot multiple times during a traffic stop. The officer shot the suspect, who is in critical condition.

Dec. 17: An Aurora police officer slipped on ice and unintentionally shot an unarmed man suspected of belonging to an auto theft ring, the department said. The suspect is in critical condition.

Dec. 13: Enrique Gonzalez died of a gunshot wound after he was stopped by a Mountain View police officer for missing the right rear tail light assembly. Gonzalez got out of his vehicle armed, at which point the officer opened fire.

Dec. 12: An Aurora police officer shot and killed a man who was fatally stabbing his girlfriend.

Dec. 11: Jefferson County deputies shot and critically wounded 38-year-old Michael Manaois after he pointed a handgun at them. He has been transferred from a hospital to the county jail.

Dec. 8: Denver police Officer Tony Lopez Jr. was left in critical condition after being shot multiple times during a traffic stop. James Woods has been charged. Lopez was wearing a bulletproof vest.

Dec. 2: Phillip Munoz, 35, died at the scene of a shootout that left Denver police technician John Ruddy wounded. Police were serving a warrant when Munoz, who was considered armed and dangerous, tried to flee.

Nov. 30: Aurora police officers shot and killed 25-year-old Tuan Hoang after he hit an officer over the head with a meat cleaver near Interstate 225 and East Alameda Avenue and stole a police car.

Nov. 27: University of Colorado at Colorado Springs Officer Garrett Swasey was killed during an attack at a Planned Parenthood branch. Four Colorado Springs police officers and an El Paso County sheriff’s deputy were wounded. Ke’Arre Marcell Stewart and Jennifer Markovsky also were killed.

Nov. 22: Two Denver SWAT officers fatally shot Miguel Angel Martinez, who was wanted on a robbery charge. The shootout ensued after SWAT officers surrounded his home.

Nov. 10: Jason Leanard Mesaros, a 36-year-old from Loveland, was shot fatally by officers in Brighton after two high-speed chases.

Nov. 10: Police in Colorado Springs shot and wounded an armed man after responding to reports of a disturbance.

Oct. 31: On Halloween, 33-year-old Noah Harpham was killed by police in Colorado Springs during a shootout at a busy intersection. Before police approached Harpham, he fatally shot three people in a rampage just east of the city’s center.