Dirty Thirty (NYPD)

The "Dirty 30" were mostly stationed at the 30th Precinct in Harlem, Upper Manhattan. At the time, the area was known as the “cocaine capital of the world” to locals and law enforcement.[3] Police corruption was extremely high around this time, and the Mollen Commission was created to help investigate and eradicate corruption within the NYPD. Corruption was so bad that although many supervising officers did not participate, they turned blind eyes to other officers committing unlawful acts.

Sergeant Kevin Nannery took the extra step and began participating. Soon his group of officers began calling themselves "Nannery's Raiders", and participated in "booming" – making bogus radio calls to cover up illegal search and seizures on known drug dealers' apartments, where they seized drugs and stole large amounts of cash.[4] They would then sell the seized drugs straight from the 30th Precinct itself at half-market price in order to profit from their spoils.

...a gram of powdered cocaine sells for $50 to $90. In the 30th, the price is $20 to $25. An ounce, or a little more than 28 grams, goes for up to $1,200 elsewhere, more than twice what the best wholesale customers pay in the 30th Precinct. A kilogram – 1,000 grams, 2.2 pounds – can cost up to $22,000. But in the 30th Precinct kilos often go for $16,000 to $18,000.

— DEA

In one case, the sergeant and two officers stopped a man in an apartment complex, took his keys and then ransacked his apartment without a warrant. They let the man go after taking several thousand dollars worth of drugs and cash. They also participated in various extortions, with illegal drug wholesalers giving the officers weekly payoffs that ranged anywhere from $600–1,000 a week.

A squad car would pull up to a corner where these guys were working and just sit there," the investigator said. "Business had to halt. Sooner or later one of the guys would start talking, feeling out the officer. Maybe they could work something out. Maybe the cop should stop by a certain bodega. The cop goes away. He doesn't bother the corner again. At the end of the week he goes to the bodega and gets his money.

— The New York Times

In 1993, Dirty 30 officer "Otto", a.k.a. Barry Brown went undercover in an investigation against the Dirty 30. The two-year investigation included sting and surveillance operations. On the week of Sept 28, 1994, 29 police officers were arrested, with five pleading guilty. A total of 33 officers were arrested.[5] The perjury committed by these officers also resulted in at least 50 of their cases being dismissed.

• Crime in Harlem