Relatives of a Minneapolis woman who was fatally shot by a police officer responding to her 911 call have filed a federal lawsuit claiming the officer who fired and his partner conspired to cover up evidence by not turning on their body-worn cameras and later hiding behind a "blue wall of silence."

The 45-page suit was filed Monday in U.S. District Court in Minneapolis on behalf of Justine Ruszczyk Damond's father, John Ruszczyk, who lives in Australia and is the trustee of her estate. The suit, which refers to her as Justine Maia Ruszczyk, seeks more than $50 million in damages.

Damond, 40, was killed on the night of July 15, 2017, after calling police to report a possible sexual assault in the alley behind her home in the 5000 block of Washburn Avenue S. According to the lawsuit, then-officer Mohamed Noor and his partner, Matthew Harrity, had completed their sweep of the alley and were starting to their next call when Noor shot Damond from inside a police SUV, striking her in the lower abdomen.

Her death, which made international headlines, led to the ouster of the city's police chief and a series of reforms for the department, including tightening its body-camera policy.

Noor, who was fired earlier this year, has since been charged with third-degree murder and second-degree manslaughter, the first Minnesota officer in recent memory to be charged with murder in an on-duty killing.

Neither officer activated their body cameras before the shooting, footage from which might have illuminated the circumstances surrounding Damond's death, said her family's attorney, Robert Bennett.

"Essentially, Justine saw something, she said something, like the signs on the airport, and she got killed for doing it, and a year later we don't know why that was, we haven't had any explanation, so we're going to sue these people to find out," Bennett told reporters at a news conference Monday afternoon. "They'll have to answer our questions soon."

Noor's attorneys say he will plead not guilty at his criminal trial and argue that he used "reasonable force" that night. Noor's criminal attorney, Thomas Plunkett, referred questions about the lawsuit to the city.

Also named in the suit with Noor and the police leadership at the time is Harrity, who the complaint alleges carried out a "conspiracy to cover up the true facts surrounding the killing of Justine."

John Elder, a Police Department spokesman, said Monday that an internal affairs investigation of the incident was ongoing, pending the outcome of the criminal case. He declined further comment, instead referring questions to city attorney Susan Segal, who said her office was reviewing the suit.

"The loss of a life, the loss of Justine Ruszczyk, is a tragedy," Segal said in an e-mailed statement. "Meanwhile, serious criminal charges are currently pending against Mohamed Noor, and it's critically important that the criminal case be allowed to proceed through trial without interference."

Damond's father is seeking $50 million in damages, a figure that Bennett, the attorney, said is also intended to prod police leaders to address some of the department's "systemic issues."

In a statement, Don Damond wrote that every step of the way, from recruitment to training, "the department needs to ensure that officers are capable of making good, skillful decisions — while fully embracing the sanctity of life — in even the most stressful situations. Although nothing can bring Justine back, I hope her legacy will help lead to a complete transformation of police culture and training in Minneapolis and all communities."

Speaking to reporters Monday, Bennett cited news reports that dozens of fellow officers, acting on the advice of union attorneys, had refused to cooperate with state and local investigators. Bennett, who specializes in police misconduct cases, said the officers' conduct forced County Attorney Mike Freeman to convene a grand jury to gather the evidence to charge Noor.

"It's well-established the blue wall of silence exists in Minneapolis," he said, referring to the unwritten code against testifying against fellow officers.

He said that Noor and Harrity had "conspired" to keep their body cameras off during the incident in an effort to conceal "evidence that would incriminate Noor, evidence that would expose the false statements of Harrity, and evidence that would show the public and the jurors in both the criminal and civil trials the truth of the circumstances of Justine's death," the suit stated. "Noor and Harrity did so to protect themselves — to insulate any lies they might later tell."

He chided department leaders for failing to hold officers accountable for not turning on the devices.

Bennett also accused Harrity of telling "one story first to the supervising sergeant and a second story to the BCA [the state Bureau of Criminal Apprehension] at a later date. [Noor and Harrity] acted together."

Police union President Lt. Bob Kroll declined to comment about the suit other than to say that any "blue wall of silence" among the rank and file is a "myth."

Noor has not given an interview to investigators since the shooting. Bennett said that while Noor's decision to invoke his Fifth Amendment rights against self-incrimination complicates the criminal case against him, his silence could weaken his defense in the eyes of a civil jury.

Harrity, who has returned to duty on the force, has told investigators he feared for his life in the moment before Damond's shooting behind the home she had shared since March 2015 with fiancé Don Damond. The two planned to marry in Hawaii in August 2017.

Harrity "perceived his life was in danger, reached for his gun, unholstered it and held it to his rib cage while pointing it downward," the charges filed against Noor read. But, the suit pointed to discrepancies in what he told a supervising sergeant at the scene of the shooting and what he later said to state investigators after consulting a Minneapolis Police Federation attorney.

The officer raised new claims that he failed to mention at the scene, according to the suit, among them: that he heard a voice and a noise before the shooting, and believed his life was in danger.

In a statement Monday afternoon, Don Damond said the complaint "sends an unmistakable message to the Minneapolis Police Department: Seismic change is needed." Bennett said Damond had no legal claim "under the quirks of Minnesota law."

Along with Noor and Harrity, the other co-defendants are: Janeé Harteau, who was police chief when Damond was shot; Police Chief Medaria Arradondo, Harteau's assistant chief at the time; and the city of Minneapolis. A voice mail left for Harteau went unreturned on Monday afternoon.

Staff writer Erin Adler contributed to this report. • 612-673-4482 • 612-673-4064