WASHINGTON – The Justice Department announced Tuesday that it would not bring federal criminal charges against two Cleveland police officers in the 2014 killing of 12-year-old Tamir Rice, saying the video of the shooting was of too poor quality for prosecutors to conclusively establish what had happened.

In closing the case, the department brought to an end a long-running investigation into a high-profile shooting that helped galvanize the Black Lives Matter movement and that became part of the national dialogue about police use of force against minorities, including children. The decision, revealed in a lengthy statement, does not condone the officers' actions but rather says the cumulative evidence was not enough to support a federal criminal civil rights prosecution.

Tamir was playing with a pellet gun outside a recreation center in Cleveland on Nov. 22, 2014, when he was shot and killed by officer Timothy Loehmann, who is white, seconds after Loehmann and his partner, officer Frank Garmback, arrived at the scene. The officers were called to the recreation center after a man drinking beer and waiting for a bus had called 911 to report that a "guy" was pointing a gun at people.

To bring federal civil rights charges in cases like these, the Justice Department must prove that an officer's actions willfully broke the law rather than being the result of a mistake, negligence or bad judgment.

In a statement, Subodh Chandra, an attorney for the boy's family, said the Justice Department's "process was tainted" and the family has demanded prosecutors provide additional information about recommendations made during the probe.

"It's beyond comprehension that the Department couldn't recognize that an officer who claims he shouted commands when the patrol car's window was closed and it was a winter day is lying," Chandra said.

The Justice Department says seven use-of-force experts — three retained by the family, four by local authorities — reviewed the recording, but the poor quality of the video on which they relied and their "conflicting opinions added little to the case." The experts used by the family said the shooting was unreasonable while the four others said that it was reasonable.