Federal prosecutors will not pursue a case against the NYPD officers who shot and killed 28-year-old Mohamed Bah in Harlem in 2012, according to a release from the U.S. Attorney's office.

NYPD Emergency Services Unit officers killed Bah in his apartment on September 25th, 2012, after his mother, Hawa Bah, called 911 to report he was having a "mental health crisis." Cops claimed Bah was wielding a 10-inch knife when they tried to enter his residence, and that he was fatally shot after he lunged at them. In 2013, a Manhattan grand jury declined to indict the involved officers, ruling the NYPD was justified in its use of force.

But Bah's family has insisted Bah was not armed when the NYPD entered his apartment, and have long argued the department has tried to cover up its officers' misconduct—the alleged knife, for instance, has not been produced as evidence, with the NYPD claiming it was destroyed during Hurricane Sandy, and lawyers believe one of the officers accidentally tasered another officer, leading the tasered cop to erroneously believe Bah was stabbing him.

Bah's family has lobbed a $70 million civil lawsuit against the city, and has been pushing federal officials to investigate Bah's death. "The only crime Bah committed at that point was being black, Muslim, and having a mental health crisis," Debra S. Cohen, one of the family's attorneys, said last year. "There was no legal justification to bust through his door."

But today Joon H. Kim, the Acting US Attorney for the Southern District of New York, told Bah's family that he is closing the investigation into Bah's death. Kim's office "determined that there is insufficient evidence to meet the high burden of proof required for a federal criminal civil rights prosecution," according to the release, and "Neither accident, mistake, fear, negligence, nor bad judgment is sufficient to establish a federal criminal civil rights violation."

Cohen told Gothamist her clients were "very disappointed" by the federal court's decision. "Unfortunately, the standard that has to be met by the Justice Department to win such cases is very, very high," she said. "The law is written in a way that you essentially have to prove beyond reasonable doubt that the officers intended to cause the harm that they inflicted on Mr. Bah."

Still, the Bahs plan to move forward with their lawsuit. In January, a Manhattan Federal Judge ruled the Bahs could take their $70 million civil suit to trial. "What we're doing now is turning our attention 100 percent to the civil trial. We have a very different standard which will allow us to put before the jury the whole story of what occurred that night, and our hands are not tied by the very high burden that the government had," Cohen said. She added, "We will do everything we can to get justice for Mr. Bah, by showing a jury that these police officers acted wrongfully and, as a result, caused his death."

The civil trial is expected to begin on November 1st.