A ticket-fixing case that embarrassed the New York Police Department nearly three years ago before fading from the headlines is finally unfolding in a Bronx courtroom, laying bare the conflicts of police investigating their own.

Sitting at the defense table Friday was Jennara Cobb, an NYPD lieutenant charged along with more than a dozen other officers with the nation’s largest police department. She listened impassively as a former colleague in the Internal Affairs Bureau testified about Cobb’s role in leaking confidential information — and about their former friendship.

“She was a sounding board,” said Detective Randy Katokofsky. “She was a good person to talk to.”

The testimony was long in the making: The case was first announced in October 2011, sparking a debate over the informal practice of police officers squashing tickets or minor summonses as favors for friends and relatives. Prosecutors portrayed it as a pervasive form of corruption. Union leaders contended it was a harmless, time-honored courtesy that never involved bribery and was even condoned by NYPD brass.

The cases alleging criminal misconduct stalled in state Supreme Court in the Bronx — a courthouse notorious for its backlogs — as lawyers sparred over whether wiretaps of officers discussing ticket-fixing were admissible. Meantime, the department quietly punished hundreds of other officers accused of administrative violations by docking their pay and putting them on probation.

Cobb’s case was the first to reach a nonjury trial in state court this week on charges that, after serving in internal affairs, she compromised the probe by warning another lieutenant and a police union representative delegate about the investigation in a brief conversation in a suburban New York bar in 2010.

That fed rumors that almost sabotaged the investigation by causing spooked union representatives and other targets to clam up and start using “burner” cellphones, prosecutor Donald Levin said in opening statements.

Cobb, 38, the highest ranking officer charged, “betrayed her oath of office,” Levin said. “It is a direct result of the defendant’s leak that this wiretap almost went down in its entirety.”

The defense has argued the case sprung from a clumsy interal investigation led by an overzealous Katokofsky and conducted in an “incestuous” setting where leaks about it were rampant long before Cobb became a suspect. Defense attorney Philip Karasyk also told the judge in his opening statement that the two officers from the bar were out to protect themselves, taking “an immunity bath” in exchange for their testimony against Cobb.

On Friday, Katokofsky testified that Cobb had worked on a drug case against a rogue officer that inadvertently triggered the wider probe. A wiretap on the officer’s phone revealed that he “was doing a lot of ticket fixing,” he said.

The information prompted investigators to get court permission to eavesdrop on the phone calls of uniformed union representatives in Bronx precincts, the detective said. The investigators learned that people who were ticketed were contacting the representatives, who would either tear up the tickets or get an officer “to forget his testimony” if called to traffic court, he added.

“You mean commit perjury?” a prosecutor asked.

“Yes,” he responded.

(AP)