A suspect was taken into custody Monday in the fatal broad-daylight shooting of a man on a Queens subway platform, according to police sources.

“We have a person in custody,” a high-ranking police source said. “Motive is gang-related.”

The suspect has not been arrested, but cops are questioning him at the 115th Precinct station house, the source said.

The 20-year-old victim was killed by a single bullet on the No. 7 train platform at the 90th Street station Sunday afternoon after a scuffle with two other men that spilled from the train, sources said.

Police sources have identified the victim as Abel Mosso of Queens.

The gunman fired a total of six rounds, according to video of the incident shared on social media.