Chief among them is who shot whom?
In all, there were more than 50 shots fired - 46 of them by New York City police officers.
One man was killed, another is critical and two cops were wounded.
And the lawyer for Angel Alvarez, who remains in Harlem Hospital, says his client has at least 20 bullet wounds all over his body.
"He appeared to have a gunshot wound to his face, chest, abdomen, perhaps arms and legs," John Carney, Alvarez's attorney, said.
Police say it started with a struggle between Alvarez and Luis Soto over a gun and ended when police responding to the scene fired 46 shots.
"Witnesses say Alvarez had the gun in his possession, and other witnesses say that Soto had the gun in his possession, and witnesses say there was a struggle over the gun, so they may have both have had possession of the same gun," NYPD Commisioner Ray Kelly said.
Soto was killed in the hail of police gunfire. Alvarez is listed in critical but stable condition.