The mother of a man whose 2014 shooting by Philadelphia police galvanized the Black Lives Matter movement in the city has withdrawn a federal civil rights lawsuit tied to his death.

Tanya Brown-Dickerson — mother of Brandon Tate-Brown, fatally shot during a traffic stop in Mayfair — offered no specific explanation for her decision to drop the wrongful-death case against the city, which had been scheduled to go to trial on Monday.

She "and the family are facing a contested trial in which it is not possible to know how the jury or the court might rule," her lawyer, Brian Mildenberg, wrote in a Sept. 13 motion seeking dismissal of her case. His filing also suggested that family health issues may have played a role in the decision.

Brown-Dickerson declined to comment on the dismissal Thursday through Mildenberg, who also refused to discuss his client's reasoning.

He added in his court filing that Brown-Dickerson "cannot and should not be criticized for her decision … nor should her decision be taken to mean that she approves of the police officers' conduct, in any respect whatsoever."

Tate-Brown, 26, was driving a Dodge Charger from the rental company where he worked when he was stopped on Dec. 15, 2014, by Officers Nicholas Carrelli and Heng Dang in the 6600 block of Frankford Avenue.

Police initially alleged that Tate-Brown was reaching inside the car for a loaded .22-caliber semiautomatic pistol wedged into his car's front seat when Carrelli shot him in the back of the head. A police investigation determined that the shooting was justified as Carrelli feared that Tate-Brown was moving toward the gun during their struggle.

Officials, however, were later forced to acknowledge that Tate-Brown had not been reaching into the passenger side to grab his gun when he was shot but was actually rounding the back of his Dodge Charger in what Carrelli feared was an attempt to reach the gun in the car.

Charles H. Ramsay, then the city's police commissioner, blamed the error on his department's rush to provide the public with facts about the case.

"One thing doesn't change: there was a gun in the car," he said in 2015. "The officer saw the gun. There was a struggle. There was an attempt to get back to the car. There were witness statements that confirmed that."

Then-District Attorney Seth Williams ultimately decided not to pursue criminal charges against the officers. But Tate-Brown's death ignited protests across the city and calls for police reform. In response, the Police Department began releasing the names of officers involved in fatal shootings.

Hillary Clinton highlighted the case during her presidential campaign last year, meeting with Brown-Dickerson and other mothers who had lost children in police-shooting incidents.

In her lawsuit, Brown-Dickerson sought damages for wrongful death, false arrest, and various civil rights violations. She also called on the court to supervise a series of recommendations the U.S. Department of Justice released in 2015 to reform the Police Department's deadly-force tactics.

Asa Khalif, Tate-Brown's cousin and prominent spokesman for the Black Lives Matter Movement in Philadelphia, remained critical of police and prosecutors in a statement released this week in response to the withdrawal of the lawsuit.

"No amount of money can be a substitute for Brandon's life," he wrote. "No amount will relieve the physical and emotional pain I and my family endure every day."