WASHINGTON — In a stunning legal reversal, federal prosecutors relented Friday and set the stage for a new trial of the man convicted in 2010 of killing former intern Chandra Levy. Acting just days before a series of courtroom confrontations, the prosecutors advised defense attorneys that they would no longer oppose a motion for a new trial for Ingmar Guandique.

If the judge grants the defense request, the prosecutors’ unexpected decision will return to the national spotlight a murder mystery that most thought had been long-since solved. A date for the new trial has not yet been set.

In a statement, the U.S. Attorney’s Office said: “We remain firm in our conviction that the jury’s verdict was correct and are preparing for a new trial to ensure that Mr. Guandique is held accountable. The U.S. Attorney’s Office is deeply committed to ensuring that justice is served in all of its cases.”

Guandique’s attorneys praised the decision.

“The government’s case against Ingmar Guandique was based on a lie,” defense attorney Jonathan Anderson said. “We are gratified that the government has now acknowledged that it cannot defend this conviction, and we look forward to justice being served in a new trial.”