A grand jury declined for a third time to indict a D.C. woman accused of assaulting an FBI agent during an inmate swap with ICE – a rare loss for federal prosecutors that could foreshadow further trouble if the case goes to trial.

U.S. Attorney Jeanine Pirro’s office said in a filing Monday it would move ahead with charging Sidney Lori Reid with a misdemeanor for the alleged assault outside the D.C. Jail in July. A magistrate judge had given prosecutors until Monday afternoon to secure an indictment against Reid or see the felony version of the assault charge dismissed.

A grand jury declining to indict three times on the same case is a warning the evidence may not stand up at trial, according to attorney Christopher Macchiaroli, a partner at Silverman Thompson Slutkin White who previously served as an assistant U.S. attorney in the federal prosecutor’s office in D.C.