MADISON, Wis. (AP) — Two court-appointed prosecutors declined Wednesday to charge a Wisconsin sheriff’s deputy in the 2016 fatal shooting of a man sleeping in a park, saying they didn’t believe they could defeat a self-defense argument.

The decision echoes a district attorney’s finding years ago that Joseph Mensah had acted in self-defense when he shot Jay Anderson Jr., one of three people he fatally shot over a five-year span.

Mensah was a Wauwatosa police officer at the time but has since become a Waukesha County deputy.

The special prosecutors, Milwaukee attorney Scott Hansen and La Crosse County District Attorney Tim Gruenke, spent months reviewing the case, consulting judges and attorneys and even conducting a mock trial with a jury, and repeatedly found they couldn’t overcome the self-defense argument. Ethical considerations prevent prosecutors from charging cases they know they can’t prove beyond a reasonable doubt, Hansen said.

“I’m only sorry that there’s nothing that we can do to help heal those wounds,” Hansen told Milwaukee County Circuit Judge Glenn Yamahiro as Anderson’s family looked on from the courtroom’s gallery. “But there isn’t. And that’s our conclusion.”

Mensah came upon Anderson, who was 25, sleeping in a car after hours in a Wauwatosa park in June 2016. Mensah said he fired after Anderson reached for a gun on the passenger seat, and Milwaukee County District Attorney John Chisholm declined to charge Mensah later that year. Chisholm also chose not to charge Mensah in the deaths of either of the other two people he killed.

Anderson’s family disputed that Anderson had reached for the gun. Their attorney, Kimberly Motley, used an obscure legal maneuver similar to a grand jury inquiry to persuade Yamahiro that there was enough probable cause to support charging Mensah. He appointed Hansen and Gruenke in December as special prosecutors to review the case and file charges if they saw fit.

Motley argued Wednesday that Gruenke and Hansen were required by law to file charges since Yamahiro ruled enough probable cause existed to support a complaint.

“This law was put on the books to protect people that are victims, as my clients are,” Motley said.

Yamahiro said he believes the statutes required him only to find probable cause and launch a review. He said that self-defense is difficult to overcome and Hansen was right when he said prosecutors can’t ethically charge cases they know they can’t prove.

He sympathized with Anderson’s family but said he never thought a case against Mensah was a “a slam dunk.”

“I am sorry from that perspective this is not a more satisfying outcome for them,” he said.

Linda Anderson, Jay Anderson Jr.’s mother, told the judge that all the work that went into forcing the second review had “been for nothing.”

“I’m not stopping until that man is behind bars where he needs to be,” she said, drawing applause from the gallery.

Mensah’s attorney, Jonathan Cermele, didn’t immediately respond to an email message following the hearing.

Mensah joined the Wauwatosa Police Department in 2015. That year, he fatally shot Antonio Gonzales, who prosecutors said had refused to drop a sword. Mensah killed Anderson the following year. In 2020, he shot and killed 17-year-old Alvin Cole as Cole fled from police following a disturbance at a mall. Mensah said he fired because Cole pointed a gun at him. That shooting sparked months of protests.

In explaining his rationale for not charging Mensah in Cole’s death, Chisholm said evidence showed, among other things, that Cole fled from police carrying a stolen handgun, fired a shot while fleeing and refused police commands to drop the weapon.

Mensah is Black, as were Anderson and Cole. Gonzales identified as Native American.

Hansen and Gruenke wrote in a 25-page report summarizing their investigation and conclusions that the Gonzales and Cole shootings were relevant to Anderson’s case and if they tried to tie the shootings together in court a judge wouldn’t permit it.

They added that Mensah put himself in danger during his encounter with Anderson by approaching Anderson’s vehicle from the passenger side rather than the driver’s side, using his squad’s floodlights rather than its emergency lights, not waiting for backup officers and failing to keep Anderson’s gun in sight. None of that, however, changes whether he acted in self-defense at the moment he opened fire, they said.

Mensah resigned under pressure from the Wauwatosa Police Department in 2020 and joined the Waukesha County Sheriff’s Department.

The Anderson family has filed a civil lawsuit against Mensah in federal court. Motley said after the hearing that’s she looking forward to deposing Mensah under oath.