When a young mother was found slain at a Brooklyn Park apartment complex last fall, it took homicide detectives little time to unravel the case.

Under the cover of darkness, charges say, two teenage boys had kicked in the door and confronted Zaria McKeever at the behest of her jealous ex-boyfriend. The 15- and 17-year-old brothers brandished a borrowed handgun — the younger one allegedly firing the fatal shots that cut down a woman he barely knew.

Surveillance video, witness statements and physical evidence helped tie them to the crime scene. Prosecutors moved to certify the minors as adults so they could stand trial for second-degree murder alongside Erick Haynes, the 22-year-old man suspected of orchestrating the home invasion. But last month, Hennepin County Attorney Mary Moriarty abruptly changed course, offering the teens a plea deal in exchange for their testimony against Haynes.

If they chose to cooperate, both boys could avoid a lengthy adult prison sentence and instead serve two years at the juvenile correctional facility in Red Wing before returning home on an intense form of extended probation lasting until their 21st birthday.

The case marks a seismic shift in how the state's largest county attorney's office handles youth violence and also fulfills a core campaign promise by Moriarty, a former chief public defender who earned a resounding victory to become the top prosecutor last fall by preaching the merits of criminal justice reform. Before taking office, she pledged to limit the number of petitions seeking adult certification with the intent of offering teens more services within the juvenile system.

The decision incensed McKeever's family and many community members, who felt betrayed by what they viewed as lack of accountability for the killers and a miscarriage of justice for survivors, especially the 1-year-old daughter McKeever left behind.

"It was choked down our throat without any concern about how we felt," said her stepfather, Paul Greer. "We will not stand for it."

Assistant Hennepin County Attorney Leah Erickson, who spent months aggressively pursuing criminal charges against the teens, told McKeever's family that she voluntarily removed herself from the case in protest. Erickson declined to comment.

In an interview, Moriarty defended the decision — and her overall approach to prosecuting juveniles, citing research on adolescent brain development that suggests a child's mind is not fully formed until age 25.

"Our goal is to treat kids like kids," she said, noting that incarceration can lead to worse outcomes for teens who often come back out a greater threat to public safety. "We know that kids that age are impressionable, they are impulsive, they're easily manipulated and subjected to peer pressure."

That manipulation, combined with the suspected gunman's age and lack of criminal record, played a significant role in her decision. "It's pretty clear that this was [Haynes'] idea," Moriarty said. "He gave them the gun, he drove them over there, waited in the car and disposed of the gun afterwards."

She plans to seek an aggravated sentence for Haynes, who was scheduled to appear before a grand jury on first-degree murder charges when his lawyer filed a motion questioning his competency to stand trial. Should he be ruled competent to proceed, he may still face an indictment for the upgraded charge.

But that was not enough to appease residents who argued that such a light sentence for his teenage accomplices would send a dangerous message to troubled youth who reach for guns to settle petty feuds.

"Mary is doing this for the Black boys thinking she's righting a [historical] wrong. But she's opening up a can of worms," said Latonya Reeves, chair of the Minnesota Civilian Public Safety Commission. "This is not what we meant when we said, 'Save our kids.'"

Moriarty conceded that the sudden change in direction prompted many difficult conversations among staff members who'd spent time working alongside the grieving family.

"That's to be expected," she said. "I can acknowledge that this is tremendously painful — and know that we are making the right decision in this case, based on science and everything we know about about young people."

'Her life was just beginning'

In the early morning hours of Nov. 8, Haynes drove two juvenile friends to the Eden Park apartment complex on a mission to kill McKeever's new boyfriend, charges say.

In the car, he gave the younger boys a firearm he'd purchased, then ordered them inside. They burst through the door and briefly argued with McKeever before firing multiple rounds. Her boyfriend, who was in the bathroom at the time of the shooting, jumped out a second-story window and ran for help.

Haynes has a history of violating domestic no-contact orders against McKeever, the mother of his child. In the weeks preceding her death, investigators found that Haynes repeatedly stalked and harassed her.

Although Haynes is accused of plotting the attack, McKeever's loved ones believe the teens are equally culpable for choosing to pull the trigger on his behalf. Relatives supported prosecutors' original plan to seek an adult criminal conviction in the case and balked at the idea of suddenly remanding the boys to juvenile court.

"She was very special and her life was just beginning," Greer said of his 23-year-old stepdaughter. "We do believe that there are some [teens] that can be rehabilitated, but they didn't just carjack. They stole a life — and we're paying the sentence for it for the rest of our lives."

Community activists, some of whom spent many years incarcerated for gang-related violence in their youth, insisted that if the kids were old enough to commit such a heinous act then they should be old enough to suffer the consequences.

"We have to stop slapping these kids on the wrist and giving them that thought, that they can go terrorize neighborhoods, even be murderers, and they don't have to look at nothing but a simple stay over at Red Wing for a year or so," said Miki Frost, founder of the 8218/Truce Center in St. Paul, an organization working to de-escalate youth disputes. "That's just not fair to the community."

The plea agreement, first reported by KARE 11, is contingent on the teens' willingness to testify against Haynes. Both boys would be placed on extended jurisdiction juvenile, or EJJ, a form of extended probation that holds a suspended adult sentence over a minor's head until age 21. A violation of their probation following release from Red Wing could trigger an immediate trip to adult prison.

So far, only the older boy has accepted the deal.

Supporters of McKeever's family are calling on the judge to reject the plea. They're expected to protest outside the juvenile detention center in downtown Minneapolis on Wednesday afternoon ahead of the next juvenile court hearing.

In an hourlong meeting Friday, exasperated relatives peppered Moriarty with questions, demanding to hear her rationale for the abrupt change of course. She explained that sending children to prison is traumatizing and often results in more difficulty reintegrating back into society when they are eventually released in their mid-30s.

In an audio recording obtained by the Star Tribune, Moriarty apologized for how the situation had played out, but held firm in her belief that the system has the best chance of rehabilitating the brothers at Red Wing.

"Murder is the highest crime someone can commit, so I'm just struggling to figure out how you're going to feel safe putting someone back out on the street in a few years that committed murder," Greer replied. "Will you accept it if one or both of them get out and kill again? ... The blood would be on your hands."

Moriarty acknowledged they weren't likely to ever agree.

Rather than enacting a blanket policy, Moriarty is examining individual cases to determine whether they merit adult certification or can remain in juvenile court. That threshold will not be determined simply by the type of charges a minor faces.

"The decisions that we make are very subjective," she said. "There are some cases that should be charged with the highest charge possible and there are other cases that don't fit that."

Staff writer Kim Hyatt contributed to this report.