New surveillance video released by the NYPD captures the moment a gunman opens fire in a Brooklyn gambling den — killing one man and wounding three others.

Rodney Maxwell, 58, was gunned down around 10:40 p.m. Oct. 7 when a fight broke out in the first-floor back room of a decrepit brick building on Hegeman Avenue near Osborn Street in Brownsville, police and sources said.

Maxwell took a fatal bullet to the chest, and three other men, ages 31, 32 and 44, also were injured in the shooting and hospitalized in stable condition, authorities said.

The video, released by the police late Thursday, shows three men wandering into the building and walking through a narrow passageway with trash and debris piled high.

One man is shown opening fire.

No arrests have yet been made in the shooting.

Maxwell lived in the St. Albans section of Queens.