After Officer Pedro Serrano decided to testify in federal court about what he sees as wrongdoing within the New York Police Department, a rat sticker appeared on his locker.
That was the least of his problems.
Serrano claims he's been harassed, micromanaged and transferred to a different precinct and put on the overnight shift.
"They have their methods of dealing with someone like me," he said in an interview.
Serrano and other whistle-blowers testified in a civil rights case challenging some of the 5 million street stops made by police in the past decade using a tactic known as stop and frisk.
They believe illegal quotas are behind some wrongful stops of black and Hispanic men.
"A lot of people told me not to come forward because of what would happen -- they said the department would come after me," Serrano said.
Several other officers and police brass testified to the opposite, saying there are no quotas and that most officers follow the letter of the law and low-performing cops like Serrano are lazy malcontents.
Under NYPD policy, officers are required to report corruption without fear of retribution.
But starting with legendary whistle-blower Frank Serpico in the 1970s, corruption scandals large and small have exposed a clannish culture that critics say encourages police officers to turn a blind eye to wrongdoing and never question authority -- or else face harassment by peers and punishment by superiors.
As a plainclothes officer, Serpico was labeled a traitor for refusing payoffs and reporting corruption. On Feb. 3, 1971, he was shot in the face during a drug raid. He recovered and testified before the Knapp Commission -- a story etched in popular culture by a hit movie starring Al Pacino.
There were several similar instances since.
"Nothing's changed," Serpico, 76, said in a recent phone interview. "It's the same old crap -- kill the messenger."
In the ongoing federal trial over the stop-and-frisk policy, lawyers for men who have sued police are seeking to show a disproportionate number of black and Hispanic men are being wrongly stopped partly because officers are under too much pressure to keep enforcement numbers up.
Serrano, along with officers Adhyl Polanco and Adrian Schoolcraft, secretly recorded hours of patrol briefings, meetings with bosses and encounters on the streets. The recordings were played at trial.
Schoolcraft, who has filed his own federal suit, was taken to a psychiatric ward in 2009 by his superiors against his will, he says. He remains suspended.
Polanco was suspended with pay for years after internal affairs officers brought charges of filing false arrest paperwork; he says the charges came because he detailed a list of complaints to internal affairs.
Serrano testified he received poor evaluations, was denied vacation and was forced to work overtime as punishment because he tallied too few arrests and stop-and-frisk reports.
"There's a whole bunch of things they do, but they're minor," he said. "But when you put it all together, it becomes a hostile work environment."
When asked whether Serrano's complaints were considered punishment, several other officers who testified said no, it's just part of the job.
After Serrano appeared in court last month, he was transferred from the Bronx to a Manhattan precinct where he now works the midnight shift.
Serpico, who adopted a pet rat after he was accused of being one, said he holds the bosses responsible. "Their message is, 'Do you want to write a summons or do you want to be delivering pizza? As a police officer, you're duty bound to refuse an illegal order. . . . But where do you go?"