The NYPD says an off-duty officer was shot during a robbery Saturday in Brooklyn.  He is in critical condition. 

NYPD investigators say the officer was shot while trying to purchase a vehicle through a transaction that was set up on social media. 

Fabien Levy, spokesperson for Mayor Eric Adams, tweeted just before 9 p.m. Saturday that an officer was shot.  

The shooter has not been apprehended and the officer's identity has not been released.  NYPD officials say he is a 5-year veteran. NYPD Commissioner Keechant Sewell says he is "fighting for his life."