It happened at 541 Court Street in Carroll Gardens around 8 p.m. on Friday.
When police arrived at the scene they found a man stabbed in the shoulder.
The victim pointed out the suspect to police outside.
As police tried to approach the suspect, they say he lunged at the officers with a knife.
Officers shot the suspect in the torso. He was taken to taken to Lutheran Hospital where he was pronounced dead.
A knife was recovered at the scene.
The stabbing victim was also taken to Lutheran where he is being treated for a wound to his shoulder.
Sources say a witness told police they saw the suspect lunge at the police and heard officers say, "Drop it, drop it."
The officers were in uniform and in a marked police cruiser.