The news came in a phone call last May, nearly two months after her son’s death, hitting Candice Lynch like a haymaker.

Since the shooting, she had gone over the events of that day countless times in her mind. It seemed like an open-and-shut case.

But now a victim’s advocate from the Hennepin County attorney’s office was calling to say that the man who shot 18-year-old Derrick Mack would not be charged. The evidence, including witness accounts and forensic evidence, backed his claims of self-defense, prosecutors said.

It was difficult to process. Within weeks of Mack’s death, detectives had two suspects, ages 18 and 23, in handcuffs. One would confess to firing the fatal bullets, according to police reports. The gun was later found, stashed in the basement of a house where the shooter stayed.

Lynch had a hard time believing prosecutors’ account of what happened that day: that Mack had gotten into the car and pulled out a real-looking BB gun with the intention of robbing the two men. That wasn’t the Derrick she knew, she said. Lynch can still remember how he could light up a room with his humor, how he freestyle rapped about anything — “You tell him to clean his room, and he would rap about it,” she said — or how he had enrolled in community college classes with thoughts of a career in the HVAC field.

But that didn’t square with the official version of events: that Mack got into the beat-up white Chrysler LeBaron near N. 39th and Colfax avenues on March 26, 2016, and pulled a gun on the two men inside. Fearing for his life, the back seat passenger, who had a permit to carry, drew his own gun and fired at Mack, the man would later tell detectives.

Police say that Mack had arranged to buy a stereo from the man driving the car, pointing to a series of phone calls between the two in the minutes before the shooting. Mack hopped into the cluttered front seat to complete the transaction, police reports suggest. Moments later he would be shot.

For now, the case remains in a sort of investigative limbo. Police consider it closed, and the detectives assigned to the case have started working new cases or since retired.

In a statement, Hennepin County Attorney Mike Freeman’s office said charges, if filed, likely wouldn’t hold up in court.

“Evidence at the time suggested that the suspect had a strong self-defense claim and we did not believe we could overcome it at trial,” Freeman said. “As a result, the Chief Deputy County Attorney for criminal prosecution undertook a second, independent review of all of the evidence and statements. He came to the same conclusion that there was a strong self-defense claim.”

Because there is no statute of limitations in murder cases, Freeman added, prosecutors would take another look at the case if new evidence were to be discovered.

The person who shot Mack, who is not named because he was not charged with a crime, could not be reached for comment. Court records show Mack was convicted in 2015 in Scott County for possessing a firearm with an altered serial number. He received probation.

A second review

On a recent afternoon, Lynch thumbed through a manila folder of autopsy records and police reports as tears welled in her eyes. She carefully spread its contents on her living room table, having committed them all to memory. She keeps a large, framed photo of Mack on an easel next to the table.

None of it made sense to Lynch, who hired private investigator Michael Grostyan to look at the case with fresh eyes.

His investigation raised questions about the contradictory statements given by the two suspects, one of whom started crying when he was brought into the interrogation room. He told detectives that he wanted to talk, but had been told not to, according to case reports. More importantly, the lack of gunpowder residue around Mack’s wounds suggested that he wasn’t shot at close range, the investigator concluded. Instead, it was likely that he was shot as he fled, his report said.

In a letter to the county attorney’s office outlining his findings, Grostyan said the suspects’ statements were inconsistent with several witness accounts of the shooting.

Furthermore, he wrote, “the shooter shot three to five shots in spite of him claiming it was self-defense.”

Armed with the private investigator’s findings, Lynch lobbied for the second sit-down in January with prosecutors. When they said they reached the same conclusion, she urged them to let the jury make that decision. She got up and walked out of the room, sobbing on the elevator ride down to her car.

She returned home to her well-kept townhouse in the northern suburbs. It still feels empty, she said. Mack was her only child.

He graduated from Osseo High School, where he made the A honor roll as a senior. His teachers wrote a letter gushing about his potential in the classroom, which the family presented to the victims reparation board.

Fighting for justice, she said, is the best way to honor him.

“It’s just been a battle just dealing with that,” she said. “I don’t think that I’ve even had time to grieve like I really should, just trying to put this puzzle together.”