A third teenager has been arrested and charged with the killing of a congressional intern in the nation’s capital, a crime that President Donald Trump cited when he announced a law enforcement surge in Washington.

Naqwan Antonio Lucas, 18, has been indicted with first-degree murder and 15 other charges for the killing of Eric Tarpinian-Jachym of Granby, Massachusetts. Lucas pleaded not guilty on Thursday.

Tarpinian-Jachym, 21, died a day after he was struck by stray bullets near Washington’s Mount Vernon Square the night of June 30.

Authorities last month arrested two 17-year-old suspects in the shooting, Kelvin Thomas Jr. and Jailen Lucas. They were charged as adults for first-degree murder while armed.

Prosecutors said Naqwan Lucas and Jailen Lucas are brothers.

U.S. Attorney Jeanine Pirro said last month that Tarpinian-Jachym was an “innocent bystander” who wasn’t an intended target of the gunfire.

Pirro’s office said he was hit when three armed suspects left a stolen vehicle and began firing shots at two young men. Tarpinian-Jachym was shot four times. Five other people also were assaulted or injured.

Naqwan Lucas faces a second indictment for allegedly killing 17-year-old Zoey Kelly on July 4. Kelly was found dead of a gunshot wound to the head inside a storage container wrapped in bedding in a bedroom closet, prosecutors said.

Naqwan Lucas also pleaded not guilty to these charges. His attorney, Steven Kiersh, did not immediately return a phone message seeking comment.

Surveillance video helped investigators identify the three suspects, police said.

Trump mentioned Tarpinian-Jachym’s killing — but not his name — during an Aug. 11 news conference where he announced a federal intervention for a “public safety emergency” in the District of Columbia.

The University of Massachusetts Amherst student was in Washington to work as a summer intern in the office of Rep. Ron Estes, R-Kansas.

—AP