Almost exactly a year ago, a Chicago cop drove to Hazel Crest for the most mundane of reasons: to buy a computer he’d found online from a 17-year-old kid and the kid’s older brother.

Within minutes, something went horribly wrong. The officer, Brandon Krueger, ended up shooting and killing the teen, Aaron Brandon, and wounding his brother, Dakuarie Brandon, now 22.

Police in the south suburb had a simple explanation. The brothers had set up Krueger to rob him, and the officer fired in self-defense. “The officer is totally a victim in this whole process,” Hazel Crest Police Chief Mitchell Davis said afterward.

What wasn’t publicly known at that time was that Krueger, an Iraq War veteran, apparently had been struggling with mental illness.

In early July — about 10 months after the shooting in Hazel Crest — the 36-year-old officer took his own life. He shot himself in a squad car in the parking lot of the South Side police station where he worked.

Now, the mother of the Brandon brothers is alleging the police account of what happened is a sham.

Last week, she sued Krueger’s estate, the village of Hazel Crest, several police officers there and the city of Chicago, alleging that Krueger’s shooting of her two sons was wholly unwarranted and that the Hazel Crest police covered up the misdeeds of a fellow officer — even going as far as claiming she played a role in her own son’s death.

A Chicago Sun-Times examination of the case has raised additional questions.

Despite the Hazel Crest Police Department saying that the Illinois State Police would investigate the lethal use of force, neither agency has said whether the shooting was justified — and it’s unclear the degree to which the issue has even been examined.

Despite the Hazel Crest police chief’s statement that Krueger was the victim, no one has been charged with attempting to rob Krueger the night of Aug. 29, 2017. Hazel Crest police didn’t respond to messages seeking comment for this story.

Additionally, Krueger appears to have spent time on medical leave with the Chicago Police Department, according to documents in his divorce case, raising questions about whether he should have been allowed to carry a gun.

In an interview with the Sun-Times, the late officer’s mother, Diane Milani, said she was unaware of the lawsuit but was aware of the events of last August. The shooting “brought back a lot of bad memories” for her son from his time in the Middle East, she added, and he seemed despondent over what had happened.

“He said, ‘That poor mom, to have to live without her son,’” Milani recalled.

Milani said she reassured her son, saying “You didn’t have a choice.”

The Hazel Crest account of what happened

Until the Brandon family’s lawsuit, the name of the officer who’d shot Aaron Brandon hadn’t been known to the public.

Krueger had been assigned to the Bureau of Organized Crime, which primarily focuses on gang, narcotics and vice investigations. At the time of his death, he’d been on the force five years.

The officer met the brothers on Birchwood Drive just before 10 p.m. on the night of the shooting. When Krueger, a Mount Greenwood resident, got out of his car, police said, Aaron Brandon pulled a gun on him while he and his brother went through Krueger’s pockets.

Krueger was driving his personal car and was dressed in street clothes, but he still had his badge and gun on him.

As the Brandons searched Krueger for valuables, police said, they found his badge and gun. One took his badge, “but before the offenders could disarm him, the CPD officer was able to fire at both offenders,” Hazel Crest police said in a statement released shortly after the shooting.

Aaron Brandon was dead at the scene. Police said they found a gun in his hand and the key fob for Krueger’s car in his pocket. Krueger’s badge was found near him, too.

Dakuarie Brandon spent a week recovering in the hospital, according to the family’s attorney, Victor Henderson.

What the Brandon family’s lawsuit alleges

Lakeisha Brandon’s complaint, however, alleges an unjustified shooting and an attempt at a cover-up by Hazel Crest police, rejecting the ideas that the Brandons had a gun, threatened Krueger with it or “made any movement or gesture to indicate that either of them was armed with a weapon.”

Instead, the lawsuit says, Krueger “fired his service weapon at the Brandons” after “a disagreement ensued.”

“From our perspective, he kind of lost it,” Henderson said, referring to Krueger. “From our perspective, it was unwarranted.”

The case Henderson filed also alleges that Hazel Crest police claimed Lakeisha Brandon played a role in her son’s death, triggering the denial of a life insurance claim that she filed to cover her son’s funeral expenses. In a letter to Henderson, the insurance company said it “turned down funding the life insurance at that time because the police had not yet ruled out the named beneficiary Lakeisha Brandon as a suspect of the homicide.”

Lakeisha Brandon also alleges that police illegally seized her cellphone, which still has not been returned to her.

The 11-count suit seeks an undisclosed amount in damages. Lakeisha Brandon has also filed a petition in probate court seeking to appoint an administrator to Krueger’s estate.

No independent investigation of lethal force?

What remains unknown is which agency — if any — investigated Krueger’s use of lethal force and whether it was justified.

In the statement released after the shooting, Hazel Crest police said their detectives were investigating the alleged armed robbery, while the Illinois State Police were investigating the use of force.

But a spokesman for the Illinois State Police said the agency’s job was not to make a determination as to the justification of the shooting, just to gather facts and turn them over to the Cook County State’s Attorney’s Office.

A spokeswoman for the state’s attorney’s office said it is not the role of prosecutors to deem a shooting justified, but to decide whether to bring charges.

A spokesman for the Chicago Police Department said the shooting would be investigated either by the Illinois State Police or the agency with jurisdiction over where the shooting occurred — Hazel Crest.

Officer’s mom: ‘Shooting was really hard on him’

Krueger’s mother, Milani, told the Sun-Times she was not yet aware of the lawsuit. She remembered her son as an “honest, kind person” who was “just heartbroken” by the shooting.

“That shooting was really hard on him,” Milani said.

Krueger told his mother that he repeatedly told the Brandons, “You don’t want to do this.”

After the shooting, Krueger, who was “very depressed after he got back from Iraq,” came upon Aaron Brandon’s obituary and started to cry when he saw a message written to the teen from his mother.

“I said, ‘Honey, you’re strong. You’ll get through it,’” Milani said through tears. “He says, ‘Mom, I’m not. That’s what you try to be, but I’m not.’”

Divorce case

Krueger’s wife, with whom he had two daughters, filed for divorce in April of this year, citing “irreconcilable differences.” They were married in May 2013 and their daughters are 8 and 2 years old.

Documents included in the court file allege a series of verbal and physical abuses by Krueger against his wife and his older daughter. At one point, she wrote a letter to Santa Claus, saying: “Dear Santa, my Dad has been so men [sic] to me and my mom and can you do sumthing Pleese!!!”

Milani says Krueger went to a local Veterans Affairs hospital and was in counseling prior to his death. His daughters, she said, “were his world.”

“He adored his children,” she said.

Two months before his death, Krueger’s wife called the police on him after he started a video chat with her in which he appeared to be trying to commit suicide, court records show.

Krueger emailed his wife on May 18 and told her that he was being placed on medical leave from CPD for at least two months, pending a psychological evaluation. He also told her that his firearm owner’s identification card had been reinstated.

Citing privacy laws, a representative for the Chicago Police Department declined to say whether Krueger was ever placed on medical leave. A spokesman for the State Police declined to comment on his FOID card.

‘Hard days and good days’

In the evening hours of July 8, Krueger fatally shot himself in the head at the Chicago Police Department’s Area South/Calumet District station at 727 E. 111th St.

Despite her filing for divorce, Milani says, Krueger’s wife “was just hoping he could get better and he could do better.”

Milani said she still speaks regularly with Krueger’s wife and daughters. “They have their hard days and their good days,” she says.

While in the police training academy, Krueger won the Thor Soderberg Leadership Award, named after the officer who was shot to death in a police station parking lot in Englewood in 2010.

After graduating from the academy, Krueger first worked in the historically violent Englewood District.

His attitude, his mother said, was “If you’re just good to people, they’ll be good to you.”