OKLAHOMA CITY (AP) — The new prosecutor in Oklahoma's biggest county announced Friday she’s dropping criminal charges against seven police officers in three separate fatal shootings from 2020, including one in which five officers were charged with killing a 15-year-old boy outside a convenience store.

District Attorney Vicki Behenna's predecessor and fellow Democrat, David Prater, had filed criminal charges against the police officers before leaving office. Behenna said she hired a use-of-force expert to examine the evidence, and her office spent hundreds of hours reviewing the three cases.

“Under Oklahoma law, these shootings were justified,” Behenna said at a news conference.

“This was not just a quick, spur-of-the-moment decision. This was a very difficult, very fact-intensive decision and review,” she said.

The charges were dismissed with prejudice, which means they are permanently dismissed and can’t be refiled, she said.

A former federal prosecutor and defense attorney from the suburb of Edmond, Behenna is the first woman elected top prosecutor in the state’s most populous county. She defeated conservative Republican Kevin Calvey last year to win a four-year term.

The most high-profile case dismissed Friday involved five Oklahoma City officers charged with first-degree manslaughter in the shooting death of Stavian Rodriguez. The teen was shot on Nov. 23, 2020, by officers responding to reports of an attempted armed robbery at a convenience store.

TV news reports of the shooting showed video of the boy dropping a gun then reaching toward his waist before being shot.

Willard Paige, the investigator for the previous district attorney, said the officers fired live rounds “unnecessarily,” and that an autopsy determined Rodriguez suffered 13 gunshot wounds.

Initially charged in the shooting were officers Bethany Sears, Jared Barton, Corey Adams, John Skuta and Brad Pemberton. All five have been on paid administrative leave since the shooting.

The teen's mother, Cameo Holland, said in a statement that she intends to work to change the law to make it easier for police to be criminally charged.

“When the district attorney of Oklahoma County apologizes to your face for the justice system failing you, it's clear we need changes in the law,” Holland said.

Behenna said Friday that she does not take these decisions lightly.

“These families are grieving," she said. “No matter what this office does or says, these families are forever changed.”

Holland has a pending civil rights excessive force lawsuit against Oklahoma City and the five officers in federal court.

In another Oklahoma City case, Sgt. Clifford Holman was charged with first-degree manslaughter in the shooting death of 60-year-old Bennie Edward.

Holman, who is white, had responded to a call of a Black man harassing customers at a business in north Oklahoma City, according to a police affidavit by homicide detective Bryn Carter. When he arrived at the scene, Holman encountered Edwards, who was holding a knife and refusing officers’ commands to drop it, the affidavit states.

The shooting sparked days of protests and demonstrations by Black Lives Matter groups and other activists.

The third case involved The Village officer Chance Avery, who was charged with second-degree murder in the July 2020 shooting death of Christopher Pool.

Avery was called to the home by Pool’s wife, who was retrieving personal belongings, when Pool ran inside carrying a bat and was shot by Avery after refusing to drop it, police said.

Gary James, an attorney for Avery and Adams, one of the officers charged in the Rodriguez shooting, said he was “ecstatic” about Behenna's decision.

“We've got seven police officers who were just doing their duty, and were placed in a position by all three of the deceased that they had to use deadly force,” James said.

Although criminal charges against police officers are not common, previous district attorney Prater — himself an ex-cop who served 16 years as the county's top prosecutor — had secured criminal convictions against officers before.

In 2013, Del City police Capt. Randy Harrison was sentenced to four years in prison for second-degree manslaughter after shooting an unarmed teenager in the back as he ran away following a scuffle.

In 2019, another Oklahoma City police sergeant, Keith Sweeney, was sentenced to 10 years in prison after a jury convicted him of second-degree murder in the shooting death of an unarmed, suicidal man.

Behenna said that in future cases involving police shootings, she will present evidence to a multi-county grand jury to make a decision on whether to file criminal charges, rather than making that decision herself.

Oklahoma City Police Chief Wade Gourley said the department has implemented “significant changes” since the fatal shootings, such as creating a training unit that has worked with every officer on de-escalation strategies. The chief's statement Friday said officers are also provided with additional less-lethal equipment, like stun guns and weapons that deploy bean bags, as well as crisis-intervention training.