The District’s fire chief, Kenneth B. Ellerbe, will not be prosecuted for allegedly assaulting a firefighter who filed a complaint with police after a confrontation at the scene of a burning ambulance, according to the U.S. attorney’s office.

Prosecutors “reviewed the matter and determined there was insufficient evidence to go forward with a criminal charge,” spokesman Bill Miller said. The decision by prosecutors was first reported by WTTG Fox 5.

The firefighter who filed the complaint, Sean Christopher Griffith, 33, declined to comment, but he said he has hired two attorneys. He had taken leave after the Aug. 13 incident, but his union representative said he has returned to full duty.

Ellerbe, who has previously denied that a physical confrontation occurred, said in an e-mail that he was not surprised by the decision and that it “confirms what I said from the beginning.”

Griffith alleged Ellerbe assaulted him at a medic call on Benning Road in Southeast Washington on Aug. 13. Ellerbe said he responded to the scene after seeing a picture of a burning ambulance posted on the firefighters union Twitter account. The chief said he wanted to know whether an on-duty firefighter or paramedic had taken the picture.

D.C. Fire Chief Kenneth B. Ellerbe (Marvin Joseph/The Washington Post)

Griffith wrote in his complaint that Ellerbe grabbed and removed a cellphone from his right hand, causing an injury. In an interview last month, Ellerbe said he asked for the phone and was given it voluntarily. He said he glanced at a blank screen and returned the phone.

Dabney Hudson, a firefighter’s union official, said that Griffith was not the person who took the photo. The fire union used the picture to demonstrate what it called shoddy equipment. City officials sought a police investigation to determine whether that fire and another one the same day were intentionally set and possibly sabotage.

That investigation has not yet been completed.