INDIANAPOLIS — Senators Todd Young (IN) and Charles Grassley (Iowa) issued a letter to U.S. Attorney General Merrick Garland pushing the Department of Justice to explain its justification for opting not to charge two former FBI officials who failed to properly respond to information about the abuse of young gymnasts.

The former FBI agents failed to quickly open an investigation of sports doctor Larry Nassar despite learning in 2015 that he was accused of sexually assaulting female gymnasts.

The Office of Inspector General found that the former agents likely provided “inaccurate or incomplete information” when investigators subsequently tried to understand what happened, but more would be needed to file charges, the department said.

“This does not in any way reflect a view that the investigation of Nassar was handled as it should have been, nor in any way reflects approval or disregard of the conduct of the former agents,” the department said.

The government last fall said it would take another look at an earlier decision to forgo charges.

Former Olympic gymnasts, including gold medalist Simone Biles, are among dozens of assault victims who are seeking more than $1 billion from the FBI for failing to stop sports doctor Nassar.

In the letter sent to A.G. Garland, Young and Grassley describe the lack of charges as “inexplicable.” The senators call for a briefing from the Department of Justice.

“In addition to being in the public interest and related to the Senate’s work, such a briefing will help to protect against this type of tragedy in the future, as well as confirm the FBI has the tools it needs to police its own and foster credibility with both the Senate and the public by ensuring justice is done when it is shown – as in this case – that FBI agents have broken the law,” the letter states.

Young and Grassley note that they requested a briefing when the DOJ’s decision was first announced but were denied. The senators are asking for a briefing no later than June 24.

The Associated Press contributed to this story.