The Justice Department last year quietly rejected career prosecutors’ bid to use a grand jury to investigate the 2014 shooting of Tamir Rice — a 12-year-old Black boy killed by Cleveland police while carrying a pellet gun — effectively ending the probe and sparking a whistleblower complaint that alleged improper political interference, according to people familiar with the matter.

Although, technically, the civil rights investigation remains open, the decision to forgo a grand jury to compel witness testimony or take other investigative steps froze the case — with the statute of limitations on one of the charges prosecutors considered most seriously set to run out later this year, the people said.

The episode reinforces how difficult it can be — because of a lack of political will and legal latitude — for federal prosecutors to investigate and bring criminal cases against police officers who kill people in the course of their jobs. Its revelation comes as the nation has seen persistent protests against police violence.

Career prosecutors had known it might be difficult to substantiate charges against the officers’ involved in Rice’s killing, but some were frustrated nonetheless that they were not allowed to conduct a full grand-jury investigation to make that assessment, the people said, speaking on the condition of anonymity to discuss the politically sensitive case. The department did not make a public announcement or notify the child’s family of its decision .

Subodh Chandra, a lawyer for Rice’s family, said Rice’s mother, Samaria Rice, cried out “I’m not ready for this!” repeatedly when she was told.

“The federal investigation was her last hope for justice,” Chandra said in a statement . “Accountability was so important to her and her family.”

He added: “The stench of political interference hovers over this case.”

The Justice Department’s behind-the-scenes maneuvers were first reported by the New York Times , which was contacted about the matter last week by lawyer David Seide, who represents a whistleblower upset about how the case was handled .

At his client’s request, Seide, who works with the Government Accountability Project, filed a complaint with the Justice Department inspector general’s office in August. Officials responded last week, saying the complaint should more appropriately be sent to the department’s Office of Professional Responsibility.

The complaint, a copy of which was provided to The Washington Post, describes how career prosecutors’ recommendation to convene a grand jury first stagnated before being rejected outright. People familiar with the events corroborated portions of the complaint, though The Washington Post was unable to locate anyone with firsthand knowledge of Attorneys General William P. Barr or Jeff Sessions intervening to overrule a career official.

The Trump administration has rolled back many Obama-era ­police-reform efforts, and Sessions and Barr have disputed the idea that police wrongdoing is widespread.

Rice was fatally shot Nov. 22, 2014, after two Cleveland police officers came to a park in response to a call about a man with a gun. Although the caller told the dispatcher that this person was possibly a child playing with a toy, that was not relayed to the officers, who handled the call as an “active shooter” situation, authorities said.

As often happens after police shootings, Ohio authorities first investigated Rice’s killing, and a local grand jury in December 2015 did not bring charges . Federal prosecutors reviewed that work, sought documents from the state and began to assess whether any federal crimes had been committed.

The federal investigation focused on officers Timothy Loehmann, who shot Rice, and, Frank Garmback, who drove the police cruiser to the scene, according to people familiar with the matter. Prosecutors in the U.S. attorney’s office in Cleveland and the Justice Department’s Civil Rights Division, along with Cleveland FBI agents, were seeking to determine primarily whether they had violated Rice’s civil rights, the people said.

A lawyer who represented the men in the past did not return a message seeking comment. Loehmann was ultimately fired from the department and Garmback was suspended. Cleveland agreed to pay Rice’s relatives $6 million as part of a civil settlement .

Federal civil rights charges are notoriously hard to bring against police officers for on-the-job conduct, as the law requires that prosecutors must show the officers knew that what they were doing was wrong. Because Rice’s killing happened so quickly, and the officers were operating with imperfect information, that might have been particularly challenging.

Even in 2016, during the Obama administration, career prosecutors in the Cleveland U.S. attorney’s office came to believe that they could not substantiate a federal civil rights case — even though they felt that what happened to Rice was horrific, according to people familiar with the matter. At the time, the Justice Department was conducting a broader investigation into the Cleveland Police Department and negotiating an agreement to mandate wider reforms.

“Nobody thought there was a civil rights case, as horrible as the entire thing was and remains,” one person said, speaking on the condition of anonymity to discuss internal deliberations.

In late 2016 — after Donald Trump had won the presidential election — then-Cleveland U.S. Attorney Carole Rendon asked Vanita Gupta, then-head of the Justice Department’s Civil Rights Division, if prosecutors could close the investigation and notify Rice’s family, people familiar with the matter said. Doing so when President Barack Obama was still in office and Loretta E. Lynch was still attorney general might have more credibility than if it were closed under Trump, one of the people said. The Obama administration had taken an aggressive posture toward promoting police reform, and officials knew Trump probably would not continue that work.

But officials in the Civil Rights Division disagreed that a case could not be substantiated, according to people familiar with the matter. Though they had not yet pushed to use a grand jury to compel witness testimony — in part because of the slow pace of getting documents and other materials from the state investigation that might bolster the cause for taking such a step — they kept the case open as the Trump administration came into office, the people said.

By 2017, the matters had largely moved out of the Cleveland U.S. attorney’s office and into the Civil Rights Division at the Justice Department in D.C., people familiar with the matter said. Two civil rights prosecutors — Jared Fishman and Nick Reddick — were assigned to work the case, and that summer they wrote a memo advocating to use a federal grand jury to push the investigation forward looking at both civil rights and obstruction crimes, which might have been easier to prove, the people said.

But the career civil rights official who would normally approve the grand-jury request, Deputy Assistant Attorney General Robert Moossy, did not do so, and the case languished, according to the memo and the people familiar with the matter.

The whistleblower complaint alleges that in September 2018, Moossy met with the prosecutors and “told them the memo had been elevated beyond his level and that a decision as to whether to authorize the grand jury investigation was being linked to another high-visibility police misconduct case: the killing of Eric Garner by New York City police in 2014.” The memo alleges that “prosecutors were told that the Attorney General and other administration officials had political concerns about going forward in both cases.”

The Garner investigation, at that point, was much further along, with prosecutors considering not just whether to initiate a grand-jury investigation, but whether to file charges. Garner’s videotaped takedown — and his last gasps of “I can’t breathe” — were caught on video, sparking racial justice demonstrations. That case had spawned significant disagreement, dating back to the Obama administration, between prosecutors in the Civil Rights Division and those in the U.S. attorney’s office in Brooklyn. People familiar with that dispute said it was far more rancorous than anything that occurred in the investigation into Rice’s death.

A representative for Sessions, who was attorney general at the time, declined to comment. Moossy also declined to comment.

After the meeting, according to the memo and people familiar with the matter, the prosecutors investigating Rice’s death told Moossy they had obtained more evidence, and Moossy asked them to prepare an additional recommendation. But again, according to the memo and people familiar with the matter, nothing happened for months.

In July 2019, the Justice Department revealed publicly that it was closing the investigation into Garner’s death without federal charges , and days later prosecutors investigating Rice’s death were told they would not be allowed to use a grand jury, according to the memo and people familiar with the matter.

Officials said at the time that Barr, who took over the Justice Department in 2019 after Trump ousted Sessions the year before, made the decision in the Garner case. But officials insisted Barr did not weigh in on the use of a grand jury in connection with Rice’s death, and that the investigation remains open.

Fishman and Reddick, dismayed generally over politicization of the Justice Department, have since left, according to people familiar with the matter.

While supervisors could reconsider whether to use a grand jury, the statute of limitations is set to expire on possible obstruction charges by year’s end.

The whistleblower complaint notes that in an August 2019 speech to a Fraternal Order of Police conference in New Orleans, Barr seemed to take aim at those seeking to hold police accountable for abuses.

“Whenever there is a confrontation involving the use of force by police, they automatically start screaming for the officers’ scalps, regardless of the facts,” Barr said, according to a copy of his prepared remarks . “I am not suggesting there are never abuses. As with all human institutions there are sometimes bad apples; and we will deal with that. But these are very much the exceptions, not the rule.”

The complaint alleges that Barr’s speech was circulated among civil rights prosecutors, and had a chilling effect.

“The implication was that they could expect to see their work attacked and interfered with by the Attorney General and his subordinates,” the complaint alleges.