New York City police have been unfairly targeting minorities with illegal searches, causing a surge in the state's mairjuana prosecutions, a recent public investigation found.

Carried out by public radio station WNYC, the investigation concluded that many of the searches were conducted in violation of people's constitutional rights.

The public radio station talked to current and former cops, defense lawyers and more than a dozen men arrested on marijuana charges who all say the New York City Police officers are abusing pat downs.

Under the law, a police officer needs to have reasonable suspicion that a person is committing a crime before he can stop someone. The officer can only pat down -- or stop-and-frisk -- the outside of a suspect's clothing if he believes there is a weapon. Only when the officer feels what he believes to be a weapon can he reach into the person's pocket.

But a number of men who have been busted for marijuana possession told WNYC that police went inside their pockets, underwear and socks without permission to pull out small bags of marijuana.

New York City law says that marijuana possession is only a misdemeanor if it is smoked or displayed "open to public view." When the drug is concealed, possession is only considered a violation, which results in a ticket and fine.

In 1977, the Marijuana Reform Act decriminalized marijuana possession of less than seven-eighths of an ounce in New York. But data uncovered by WNYC show that misdemeanor arrests are made at five times the rate of tickets for violations.

Each of the men the station talked to "said the police pulled the drugs out of his clothes before arresting him for having marijuana in public view. None of them had been buying their drugs outside. And none of them were carrying a weapon when they were stopped."

Leo Henning, an African-American man, had a bag of marijuana hidden inside his sock -- under his foot -- when police stopped him in March. The officers almost immediately put their hands on him.

"They patted me down, and they checked the outside of my sleeves of my coat," he explained. "He went into my front right pocket. Then he went into my front left pocket."

"Then he went into my right back pocket. Then he went into my left pocket."

The officer found nothing but continued searching Henning's socks.

"He stuck his hands in. His fingers was going under my foot inside my sock. That's when he felt it, I gather," he said.

Henning was arrested for displaying marijuana "open to public view" and spent the night in jail.

Of the 19 precincts with the highest rate of low level marijuana misdemeanors, 15 have majority African American or Hispanic populations.

The New York ACLU found that over two million innocent New Yorkers were subjected to stop-and-frisks between 2004 and 2010. In 2010, 85 percent of those stopped were black or Latino.

The following WNYC chart shows the precincts with the most low level marijuana arrests.