On August 9, 1997, Police Officer Justin Volpe, sodomized Abner Louima with a broken broom handle in the 70th Precinct bathroom in Brooklyn. Officer Volpe eventually pled guilty and received a sentence of 30 years in federal prison.
4- NYPD subway sodomy scandal
On October 15, 2008, five officers attempted to arrest Michael Mineo for smoking marijuana in a Brooklyn subway station. Days later, Mineo made accusations claiming he was sodomized with a police radio antenna by the officers. On December 9, 2008, the Brooklyn District Attorney announced that three of the officers, Richard Kern, Alex Cruz, and Andrew Morales, were indicted on criminal charges. According to the District Attorney, officer Kern sodomized Mineo with his expandable baton after the officers handcuffed him. Officer Kern was charged with aggravated sexual abuse and assault, and faced up to 25 years in prison, and officers Cruz and Morales were charged with hindering prosecution and official misconduct, and faced up to 4 years in prison. All three officers were acquitted of all charges.
3- Timothy Stansbury death
On January 24, 2004, Housing Bureau officer Richard Neri, Jr. accidentally and fatially shot Timothy Stansbury, a 19-year-old black man who was trespassing on the roof landing of a Bedford-Stuyvesant housing project building. Stansbury was unarmed but had apparently startled Officer Neri upon opening the roof door. At that point, Officer Neri discharged his service firearm and fatally wounded Stansbury. Although Commissioner Ray Kelly stated that the shooting appeared "unjustified", a Brooklyn jury found that no criminal act occurred and that the event was a tragic accident. Neri was cleared of all charges. The city later agreed to pay $2 million to settle a lawsuit filed by the Stansbury family. A grand jury declined to indict Neri but Kelly later suspended him for 30 days without pay and permanently stripped him of his service weapon.
2- Amadou Diallo death
On February 4, 1999, four plainclothes undercover NYPD officers working under the Street Crimes Unit fired 41 gunshots at Amadou Diallo, killing him instantly. Diallo, whom the officers mistook for a since-convicted rapist, was later found to be unarmed. The officers were subsequently acquitted, but the City of New York and the NYPD later paid out $3,000,000 to Diallo's parents in a civil suit. Following the controversy, the Street Crimes Unit was abolished three years later.
1- Sean Bell shooting incident
On November 25, 2006, plainclothes police officers Fired over 50 shots and killed Sean Bell and wounded two of his companions, one critically, outside of the Kalua Cabaret in Queens. No weapon was recovered. According to the police, Bell rammed his vehicle into an undercover officer and hit an unmarked NYPD minivan twice, prompting undercover officers to fire fifty rounds into Bell's car. An undercover officer claims he heard one of the unarmed men threaten to get his gun to settle a fight with another individual. On April 25, 2008, Arthur Cooperman cleared Detectives Michael Oliver and Gescard Isnora of manslaughter charges and Detective Marc Cooper of reckless endangerment in the death of Sean Bell.
(Source- http://en.wikipedia.org/wiki/Scandals_and_allegations_of_the_New_York_City_Police_Department )