Authorities confirmed on Sunday morning that a gun they recovered the .40-caliber pistol they think was used to kill an NYPD officer last week.
Officer Randolph Holder, 33, died on Tuesday after investigators said Tyrone Howard shot the 5-year police veteran in the head.
Divers recovered an unrelated gun on Thursday that they now said had been in the river a long time.
Police closed off FDR Drive between East 96th and East 132 streets on Sunday for about two hours, reopening the major throughway at around 10:30 a.m.
NYPD have been spotted in the area, where Howard allegedly shot Holder after the officer attempted to retrieve a stolen bicycle, since Tuesday's shooting.
Holder had reported to the scene with fellow officers after receiving a call about a shooting at the East River Housing Development in East Harlem.
An officer with PSA 5, Holder chased the armed suspect onto the FDR Drive's pedestrian overpass when Howard reportedly shot him.
The shootout with police left Howard, 30, with a gunshot wound to his leg, which was treated before he was taken into police custody.
A wake for Holder is scheduled for Tuesday at the Community Church of the Nazarene in Far Rockaway between 9 a.m. and 6 p.m.
Family, friends, city officials and fellow officers are expected at the Wednesday funeral at 3 p.m.