Ronny Flanagan took pride in his record as a police officer in Plano, Texas. He had an incident-free career. He took safety training regularly. He was known at the range as a very good shot.

Yet he killed a man when he was simply trying to press a flashlight switch mounted beneath the trigger on his pistol.

In a deposition, Flanagan expressed his remorse and made a prediction.

“I don’t want anyone to ever sit in a chair I’m in right now,” he said. “Think about the officers that aren’t as well trained, officers that don’t take it as seriously, and you put them in a pressure situation, another accident will happen. Not if, but will.”

Flanagan was right. Three months after the October 2010 shooting in Plano, a 76-year-old man took a bullet in the stomach from a New York police officer trying to switch on the same flashlight model.

At least three other people in the U.S. over the past nine years have been shot accidentally by police officers with gun-mounted flashlights, an investigation by The Denver Post found. Two victims were fellow officers.

In Colorado, Denver’s police chief banned the use of tactical flashlights with switches below the trigger guard after two officers accidentally fired their guns last year.

One of the officers may have shot a suspect when his finger slipped from the flashlight switch to the trigger, firing a bullet into a car window of the fleeing driver.

Other large Colorado police and sheriff’s departments contacted by The Post said they have recorded no flashlight-related accidental gunshots. But many have imposed restrictions similar to Denver’s.

The exception is Aurora, Colorado’s second-largest city, which allows its 670 police officers to mount any tactical flashlight model and requires no training in their use.

“It just has not been a problem with us,” said Frank Fania, a spokesman for the Aurora Police Department. “There is a distinct difference between a switch on our grip versus the gun trigger.”

He said the department had never had an accidental discharge related to tactical flashlights mounted on guns, and he credited general training on gun use to the absence of problems in Aurora with tactical flashlights.

First made for Navy SEALs

Tactical flashlights were first manufactured for the Navy SEALs, the highly trained strike force that killed Osama bin Laden. But when they entered the civilian law enforcement market, training in their use by police officers varied from mandatory to nothing.

In a check of police departments in other states, The Post found instances of other officers accidentally firing their guns when they tried to switch on their flashlights. It is impossible to know how often this happens, however, because no one tracks these incidents nationally.

In Plano, Flanagan tried to shine his flashlight on a suspected drug dealer in a dark parking lot outside a fast-food restaurant. Instead, he shot and killed Michael Alcala, leaving a 2-year-old boy fatherless.

“I don’t think it’s a very good idea to have any flashlight on a gun. You’re turning it into a loaded flashlight,” said Luke Metzler, a lawyer who sued Plano and the flashlight maker on behalf of the son, Michael Alcala Jr.

Metzler and others who searched for statistics on accidental gun discharges related to flashlights found that none are kept.

“Part of the problem is, unless someone is seriously injured or killed, reports of this are not made,” he said.

In Denver, the first accidental flashlight-related shooting occurred in January 2013 and injured no one. An officer searching for an armed suspect in a homeless camp went to turn on his flashlight as he pulled open a tent flap. He hit the trigger instead, firing one round into an empty tent.

In the second case, seven months later, the officer might have shot someone. He pulled over a suspected stolen vehicle and went to shine his gun-mounted flashlight inside. The suspect drove off. The officer stumbled, firing his gun as his finger slipped onto the trigger.

The stolen car was found abandoned. A bullet had been fired into the driver’s window and out the windshield, and “there was a small amount of blood on the driver’s seat and center console,” according to the police department’s independent monitor.

Two months later, Police Chief Robert White prohibited “any weapon-mounted flashlights that are activated by a front strap pressure switch” beneath the trigger guard. This year he required additional training for officers using approved flashlight models.

Accidents called rare

Flashlight manufacturers insist their products are beneficial to police and call accidents rare.

SureFire, the maker of the flashlight used in the shootings in Plano and the Bronx, issued a statement that more than 100,000 of its flashlights were in use, including tens of thousands with grip-activated switches.

In 25 years, the Plano shooting “was the first reported safety-related incident involving our pistol-mounted lights and switches,” the company said.

“These figures alone,” SureFire said, “(show that) weapon-mounted lights are safe.”

Some police training experts also endorse gun-mounted flashlights but caution that officers should be trained to use them safely. They also acknowledge that in stressful situations, the human hand may exhibit a jumpy “sympathetic muscle response,” in which one finger imitates the action of another.

Nationally, The Post found five flashlight-related cases where people were shot.

The first occurred in Yonkers, N.Y., on Feb. 7, 2005.

According to court records, police officers swarmed a house to arrest a suspected drug dealer and search the premises. Called by megaphone, the suspect walked out and was handcuffed. Joseph Barca and Thomas Bodkin were among the officers sent in to clear the house.

Inside, they and a third officer, Robert Akey, heard a police radio transmission that someone was moving in the basement. They found a makeshift wall blocking the basement entrance. Akey smashed it with a police shield and stepped through the hole. Bodkin followed.

Except for a kitchen ceiling light above them, the basement stairs were dark. The officers were walking into a potentially deadly encounter. Barca went to turn on the M3 Tactical Illuminator flashlight switch on his Glock 19.

He hit the trigger instead, fracturing Bodkin’s leg and sending him to a regional hospital for emergency surgery.

In a lawsuit against Insight Technology Inc., the flashlight maker, Bodkin said he “suffered grievous and permanent injuries from being shot.” The bullet left him using a cane and limping on a leg that surgery left shorter than the other.

His lawsuit alleged that the Illuminator’s on-off switch was too close to the trigger and operated by the trigger finger.

Gene Maloney, a retired master firearms instructor with the New York City Police Department, also contended that the flashlight design was inherently unsafe because “it increases the likelihood of someone pointing a loaded firearm at someone when a threat of deadly force does not exist.”

After five years of litigation, Bodkin and Insight reached a confidential settlement.

The police department and Barca declined to discuss the case.

An accidental shooting in New Jersey began with a police chase on the night of May 23, 2009. In the town of South Toms River, police officers spotted Franklin Johnson — who had a suspended license and outstanding arrest warrants — driving a maroon minivan.

They stopped him, telling him to shut off the engine. Instead, he sped away, running a red light and crossing into incoming traffic. Sgt. Joseph Howell, a Manchester Township detective riding with Lt. Daniel Evanowski of the South Toms River police, heard a radio transmission that an occupant of the fleeing car was suspected of possessing a missing police handgun.

They spotted the minivan speeding off an interstate exit ramp onto Double Trouble Road. Trouble ensued. Evanowski pulled up behind the minivan, activating his emergency lights, and rushed toward the driver’s side.

Howell jumped out to provide cover and noticed that the hand-held flashlight he wore was pointing backward. To save time, he decided to activate his weapon-mounted light instead.

“However, when he attempted to press the light switch with his right index finger, the gun discharged — most likely as a result of his finger slipping and hitting the trigger,” according to court records.

The bullet shattered a passenger window and struck Johnson’s sister, Duwana, in the shoulder.

Duwana Johnson sued. A New Jersey federal district court held that neither Howell nor the Manchester Township Police Department were liable for accidentally shooting her.

Another accidental shooting occurred in Austin, Texas, on New Year’s Eve of 2010, when Officer Melvin Moreno climbed onto a table to search an attic crawl space with his pistol-mounted flashlight. “The table overturned and Officer Moreno fell, thereby causing his firearm to accidentally discharge once and strike another officer in the tops of both feet,” according to a disciplinary report.

Moreno was suspended for three days for failing to handle his gun “with a high degree of care and caution.”

In the Bronx, Detective Andrew McCormack tried to adjust the flashlight on his Glock pistol while arresting Alberto Colon on a drug-possession charge on Jan. 22, 2011. He accidentally hit the trigger, firing a bullet into the stomach of the suspect’s father, Jose.

McCormack was using the same SureFire flashlight model, with a pressure switch below the trigger, that Flanagan used in Plano.

The shooting brought renewed anguish to McCormack and his family. His father, also a police officer, had been killed when a bullet penetrated his supposedly bulletproof shield.

Jose Colon recovered at Jacobi Medical Center, the same hospital that repaired Thomas Bodkin’s leg, but doctors were unable to remove the bullet. He returned home with it lodged in his stomach.

Two lawsuits followed the Oct. 13, 2010, fatal shooting in Plano. The city settled with the Alcala family for $245,000, and SureFire settled for an undisclosed sum.

Metzler, one of the family’s lawyers, said the settlements ensure that Alcala’s young son will be provided with everything from counseling to shoes for school. “How do you describe what a son experiences at that age?” Metzler asked. “No amount of money is ever going to make that person whole.”

Rules vary widely

Police department rules regarding flashlights on guns vary widely across the nation.

Detroit police are not allowed to have them, a spokeswoman said. In Los Angeles, police spokesman Bruce Borihahn said recruits are trained to use them and the department has been accident-free.

However, “we are not allowed to use those buttons beneath the trigger guard,” Borihahn said. “All of our on-off switches are forward of the trigger.”

The Los Angeles policy governing tactical flashlights, which was adopted in 2006, stresses that “the lighting systems are designed for use as an illumination tool, functioning as a component of the weapon system and not as a sighting device or independent light.”

That policy requires officers to complete a training course on the use of such flashlights. The officers also must pass a night-qualification shoot test before they can use such flashlights.

The Orange County Sheriff’s Department in California has enacted a policy similar to Denver’s, citing concerns in the law enforcement industry about their safety. The department said its decision was not related to accidental shootings.

Some police-training experts call tactical flashlights a lifesaving technology, especially when a few accidents are compared with the number of mistaken shootings in the dark by officers caught without flashlights.

“There’s definitely a reason to have lights mounted on firearms. You want to be able to have a free hand to open doors. In some cases, you may be trying to push someone to the ground,” said Harvey Hedden, executive director of the International Law Enforcement Educators and Trainers Association. “They’ve proved their worth.”

He and others add that proper training is essential.

Steve Ijames, a retired police chief who conducts training programs abroad, advises police to shine a gun-mounted flashlight to one side of the suspect.

“You can’t just point guns at people because you have a flashlight,” he said. “I’ve seen officers use a flashlight-mounted gun to help a person search their wallet for a driver’s license. I’ve literally seen that on a traffic stop.”

Steve Ashley, a retired law enforcement officer working as a risk-management consultant, wonders whether installing a flashlight switch beneath the trigger is wise.

“The question is, does the switch need to be in that location, and what are the ramifications?” he said. “I would not want something that minimally benefited police officers but put them at a much greater risk of hurting someone.”

Ronny Flanagan had his answer to that question. After killing Michael Alcala, he testified he would never put his flashlight back on his gun “because of the proximity of the switch to the trigger itself.”

“My perspective now,” he said, “now that I’ve walked in my shoes on this deal, it’s ludicrous to have any kind of pressure switch on a weapon. Period.”

David Olinger: 303-954-1498, dolinger@denverpost.com or twitter.com/dolingerdp

Staff writer Jordan Steffen contributed to this report.