The teenage alleged gunman faces multiple charges, including murder.
The arrest comes on the same day as funeral services were held in Brooklyn for the 15-year-old victim, Riley Billingslea.
Billingslea was shot in the head two weeks ago in an apartment in Kingsbridge Heights.
A 13-year-old boy who was grazed by a bullet during the incident told police the two older teenagers were arguing before the suspect pulled out a gun.
Billingslea had been attending military school and was looking toward a promising future.