A 17-year-old suspected gang member has been arrested for last week’s armed carjacking of an off-duty female FBI agent in Washington, DC, police said.

Schoolboy Devonta Lynch was taken into custody Monday and charged as an adult for last Wednesday afternoon’s attack as cops continue searching for a second suspect.

He was busted at home, where cops found a handgun magazine, two 50-count boxes of 9mm live rounds — and a pair of black Nike sneakers matching those worn during the carjacking, according to court documents cited by Fox 5 DC.

The federal agent said she was standing zipping up her jacket outside her car with the door open near the Lincoln Memorial when she was knocked to the ground.

She remembered lying on her back and looking up to see one of the attackers aiming a gun at her and demanding her keys and phone.

After a brief struggle, the FBI agent was overpowered and robbed of her possessions, the documents state.

The gunman and his accomplice then got into the agent’s car and sped away from the 100 block of 12th Street SE, leaving the agent with a cut lip, the filings stated.

The victim’s car was found abandoned nearby around 15 minutes later — with surveillance footage catching the suspects fleeing on foot, the documents stated.

That footage allegedly identified Lynch as the driver — and detectives also got an anonymous tip that he and the other suspect were members of the Area 71 gang, the report said.

Lynch, a student at High Road Upper School, had also been charged with assault in an unrelated incident from Nov. 9. 

Lynch was ordered held in a juvenile detention facility without bond ahead of his initial court appearance set for Monday.