That is, until Wednesday.
Baltimore Police Commissioner Frederick H. Bealefeld III stole the playbook from New York when he personally helped arrest 15 of 17 officers charged in an extortion scheme that federal authorities say involved kickbacks from owners of a tow truck company.
The top cop lured the accused officers to the training academy, took their badges and handed them to the president of the class of new recruits, who lined them up on the floor for display. The scene wasn't captured on television, but the message to those about to join the force, and to those already serving, was deliberate, and unmistakable.
Stories abound of city police officers and others in law enforcement getting caught on the wrong side of the law, but most of the cases appeared isolated to one or a handful of cops who made bad decisions.
Baltimore had managed to avoid the taint of the words "systemic corruption."
There were often hints that the uncovered misconduct was more extensive than first advertised. But not in recent memory has such a broad, sweeping case been brought. Seventeen cops charged with federal crimes Wednesday, and a dozen more implicated.
Here is a list of some of the more recent cases against Baltimore police officers and other law enforcement officials that raised questions of systemic corruption:
1996: Arson for profit
Two police officers, father and son, were sentenced to 15 months and two years in prison in 1996 for covering up an arson-for-profit scheme masterminded by a group of low-level gangsters who burned vacant rowhouses to pocket insurance money. The cops were paid to clear streets of witnesses and falsify police reports. Two people died in the fires.
1997: Ticket theft
Two officers pleaded guilty in 1997 to stealing Orioles playoff tickets from scalpers. Both officers signed their resignation papers in court as they pleaded guilty, while alleging that the practice was routine and widespread among their colleagues. No other officers were charged in the case.
1998: Drug connection
A city officer was sentenced to five years in prison in 1998 for being on the payroll of a drug lord and for helping abduct and kill a rival narcotics dealer. The drug lord was spared execution but was sentenced to life in federal prison, linked by prosecutors to more than a dozen murders and described as one of the most ruthless drug dealers in Baltimore at the time.
1999: Latino harassment
A police officer pleaded guilty in July 1999 to using his badge to rob a Latino immigrant in Fells Point under the ruse of checking immigration papers. The case strained relations with the community as more immigrants accused officers of robbing them. Only one officer was charged and convicted in connection with one robbery.
2000: Planting drugs
A police officer in 2000 was caught in an undercover sting and charged with planting drugs on an innocent man, raising questions about police tactics across the department. The case crumbled with prosecutors accusing police of bungling the investigation and charges were dropped. The accused officer later committed suicide.
2004: Former commissioner guilty
Former Baltimore Police Commissioner Edward T. Norris pleaded guilty in 2004 to public corruption and tax charges for misusing a special police fund and served six months behind bars. His top aide also pleaded guilty in the case and admitted to using money from the fund to pay for romantic liaisons, dinners at expensive restaurants, trips and gifts.
2005: Flex squad allegations
Police commanders in 2005 disbanded the Southwestern District's "Flex Squad" after an officer was charged with raping a woman in the police station. Detectives reported finding drugs haphazardly kept in desk drawers and evidence that members had been planting contraband on suspects. A jury acquitted the officer of rape and the department dropped administrative charges against other officers. Nothing ever came of the broader investigation into the squad.
2006: Drug shakedown
Two Baltimore police detectives were sentenced in 2006 to each serve more than a century in prison for shaking down drug dealers for money, and stealing cocaine and heroin for their informants. They argued that their tactics were widely used and endorsed as part of legitimate undercover work.
2006: Making up cases
Detectives opened an internal investigation in the fall of 2006 examining a sergeant and six plainclothes officers on the Special Enforcement Team in the Southeastern District who were accused of embellishing or making up cases to obtain arrest warrants. The allegations came to light when federal and state prosecutors began dropping hundreds of criminal cases involving the officers. None of the officers were charged with crimes and it's unclear what, if anything, happened with the internal investigation.
2009: Prison smuggling
At least four state prison guards were charged in 2009 with smuggling salmon and vodka to a violent prison gang and helping them arrange drug deals, extort protection money and arrange hits on witnesses and rivals on Baltimore streets. Authorities said the gang tried to take over the city's lucrative drug trade from behind prison walls with the help of prison guards.