Police took a Brooklyn high-school student into custody on Wednesday for bringing a loaded gun to school, cops said.

Security at the Unity Preparatory High School, a charter school on Driggs Avenue in Greenpoint, were alerted around 11 a.m. about a student with a gun inside the school, according to the source.

When they tracked down the 17-year-old, they found he had a loaded .357-caliber handgun, the source said.

The student, later identified by police as Corique Harrell, was arrested and charged with multiple counts of criminal possession of a weapon, according to police who said he had no previous criminal record.