The four officers involved in the fatal shooting of a man in Brooklyn are all under investigation.

Sources say Leon Dinham, Anthony Bottiglieri, Bekim Molic and Omar Rafiq are the officers who opened fire on Saheed Vassell in Crown Heights back in April. 

Several 911 calls were received reporting that Vassell was waving what appeared to be a gun around the neighborhood. 

Vassell was shot and killed by the officers after he refused to drop the object he was holding. 

Investigators later discovered it was a welding pipe and not a gun.

Police sources tell NY1 the four officers had never before discharged their firearms in the line of duty. 

Sources tell NY1 all four are under investigation by the Force Investigation Division.