MILWAUKEE — Milwaukee police officer Christopher Manney was fired by police Chief Flynn after he fatally shot a mentally ill black man at Red Arrow  park in April. This week the DA decided that Manney won’t face criminal charges.

Milwaukee County District Attorney John Chisholm said in an emailed press release that Christopher Manney won’t be charged because he shot Dontre Hamilton in self-defense.

“This was a tragic incident for the Hamilton family and for the community,” Chisholm said in a statement. “But, based on all the evidence and analysis presented in this report, I come to the conclusion that Officer Manney’s use of force in this incident was justified self-defense and that defense cannot be reasonably overcome to establish a basis to charge Officer Manney with a crime.”

Manney is at least the third police officer to not be charged in the past month after a confrontation that led to a black man’s death.

Governor Walker says the National Guard had been “activated and deployed” and will be used at the discretion of the Milwaukee Police Department to manage expected protests against the decision.

Manney shot 31-year-old Hamilton on April 30 after responding to a call for a welfare check on a man sleeping in the park. Manney said Hamilton resisted when he tried to frisk him. The two exchanged punches before Hamilton got a hold of Manney’s baton and hit him on the neck with it, the former officer has said. Manney then opened fire, hitting Hamilton 14 times.

Hamilton’s family said he suffered from schizophrenia and had recently stopped taking his medication. The family’s attorney also released a statement expressing the disappointment of the family. The statement also said  the family has reached out to the U.S. Attorney’s Office in Milwaukee and is calling for a federal investigation.

Police Chief Edward Flynn fired Manney in October, saying Manney instigated the fight with an inappropriate pat-down. The chief said Manney correctly identified Hamilton as mentally ill but ignored his training and department policy, and treated him as a criminal.

“You don’t go hands-on and start frisking somebody only because they appear to be mentally ill,” Flynn said when he announced Manney had been dismissed.

Hamilton’s death preceded those of Michael Brown in Ferguson, Missouri, and Eric Garner in New York City, but the case hasn’t attracted as much attention despite frequent, mostly peaceful protests. Hamilton’s family has used the protests to try to raise awareness about mental illness. Others said his death underlined race concerns, chanting “people of color are people, too,” and carrying signs that read “black lives matter.”

In response to Milwaukee County District Attorney John Chisholm’s decision to not file charges in the shooting death of Dontre Hamilton, Congresswoman Gwen Moore said:

“I am deeply disappointed in District Attorney John Chisholm’s decision to not press charges against Officer Christopher Manney in the shooting death of Dontre Hamilton. This decision is just one of many in recent weeks that continue to perpetuate a disheartening notion that there is a significant lapse in accountability for reckless officers and the behavior they employ in our communities.

“For those who see this decision as a miscarriage of justice, I assure you that our efforts to pursue a fair and equitable outcome for the Hamilton family are far from over. In the coming days, I will be asking the Department of Justice to conduct their own investigation into this matter to ensure that Dontre’s death will not be in vain.”

“It is paramount that we channel our collective grief and frustration in a constructive manner. We must rigorously pursue justice, including changes to police procedure and training regarding the appropriate use of force. This, not violence, will honor Dontre’s memory. As a mother and grandmother, I can’t imagine the anguish and disappointment the Hamilton family must be feeling right now. My heart goes out to them during this painful time.”

The Milwaukee Police Association condemned Manney’s firing as a political move, and members voted no confidence in Flynn soon after the firing.

Manney has appealed his firing and applied for disability, saying the shootings in Milwaukee and Ferguson have cost him sleep and made it difficult for him to think clearly. He also has said he suffers from post-traumatic stress disorder.

Milwaukee police announced in December they would accelerate training that equips officers for dealing with crises, including encounters with the mentally ill. Only about 20 percent of the force’s roughly 1,800 officers have had the training.