Scores of congressional staffers walked out on the job on Capitol Hill Thursday afternoon in a protest against grand juries' failure to hand up indictments of white policemen in the deaths of unarmed black men Eric Garner in Staten Island, New York, and Michael Brown in Ferguson, Missouri.

The contingent of about 200 mostly minority staffers left their offices at 3:30 p.m. and gathered on the steps of the U.S. House of Representatives in Washington, D.C. They all raised both of their hands in solidarity with the "hands up, don't shoot" mantra of demonstrators across the nation who have protested against what they see as the lack of justice for Garner and Brown.

The Congressional Black Associates, Congressional Hispanic Staff Association and Congressional Asian Pacific American Staff Association organized the Thursday demonstration, which was attended by vocal civil rights advocate U.S. Rep. John Lewis, a Georgia Democrat, according to the Huffington Post. The event was presided over by Senate Chaplain Barry C. Black, who offered a prayer during the protest.

Garner was killed as police officers attempted to arrest him for selling individual cigarettes outside a Staten Island store on July 17. The New York City medical examiner ruled the death a homicide resulting from neck compression that prevented breathing. The whole incident was captured on video, but a grand jury declined earlier this month to indict NYPD Officer Daniel Pantaleo, who pressed on Garner's neck using a maneuver many have described as a chokehold as Garner yelled "I can't breathe," a sentence that has become a rallying cry for protesters.

Black offered a prayer during the walkout, saying, “Forgive us when we have failed to lift our voices for those who couldn’t speak or breathe for themselves.” He emphasized the word "breathe" in the prayer, CBS DC reported. “Injustice has often been maintained because good people failed to promptly act,” Black added later.

The grand jury's failure to indict Pantaleo catapulted the Garner case into the national spotlight and sparked protests that continue to this day in cities across the country. The protests also decry the failure of a grand jury to hand up an indictment against Ferguson police officer Darren Wilson for shooting 18-year-old Michael Brown to death Aug. 9 on the streets of the St. Louis suburb. It was during the initial nationwide protests over Brown's death that "hands up, don't shoot" first emerged as a motto for the movement.

Rep. Elijah Cummings, a Maryland Democrat who has called for a congressional inquiry into the Garner and Brown cases, issued a statement Thursday, NBC News reported.

"These congressional staffers put in incredibly long hours, nights and weekends working to pass legislation to help people live better lives, so I fully support them taking a few moments today to pray with the Senate chaplain for Congress to take action to ensure that all Americans are treated equally before the law," he said.