In his 24 years as a Philadelphia narcotics investigator, Jeffrey Walker testified at countless court hearings, providing the evidence that sent dozens of drug dealers to prison.
He took the witness stand again Tuesday - this time to implicate himself and six of his former colleagues as rogue cops who terrorized the streets with gang-like efficiency.
As long as the Narcotics Field Unit kept the headline-grabbing drug busts coming, he told a federal jury, its supervisors never asked too many questions.
"We produced big jobs. They liked that," he said. "As for the bosses, it's nothing but a dog and pony show."
Over five hours, Walker painted a devastating portrait of the tactics members of his elite narcotics squad employed to keep drugs off the street, the bosses happy, and their own wallets fat.
As he told it, they lied in court hearings, planted evidence, and conducted dozens of illegal searches, asking for warrants after the fact.
They beat up drug suspects and pocketed their money. And over beers after work, they would proudly compare themselves to dirty cops in the movie Training Day or the corrupt Los Angeles drug squad in the TV series The Shield.
"We used to joke," the 46-year-old disgraced officer turned star government witness said, " 'That's all Hollywood. This is real life. They ain't got nothing on us.' "
Slump-shouldered, paunchy, and dressed in a drab prison jumpsuit, Walker cut a far different figure on the witness stand than the dreadlocked enforcer that others have described from their encounters with him in his prime.
With his testimony, prosecutors sought to establish the backbone of their case against Officers Thomas Liciardello, Brian Reynolds, Perry Betts, Michael Spicer, Linwood Norman, and John Speiser.
Walker began cooperating with the FBI following his own arrest in a 2013 FBI sting. After he was caught planting drugs and robbing a suspect's house, he said, he flagged for agents the 20 questionable drug busts that now make up the case against his former colleagues.
Asked Tuesday why he agreed to turn on the rest of the squad, Walker replied, "I decided I wanted to save myself."
That answer is likely to provide ample ammunition as defense lawyers get their chance to cross-examine him Wednesday. Already, they have referred to Walker in court as a "despicable, rotten liar and thief," and a "narcissistic, amoral creep."
Under questioning Tuesday from Assistant U.S. Attorney Maureen McCartney, Walker matter-of-factly walked jurors through his career as a rogue cop - from the first time he pocketed drug money as a young officer in West Philadelphia's 16th District to the bigger hauls and bigger paydays after he joined the Narcotics Field Unit.
They operated under the leadership of Liciardello, he said, who directed them to a certain type of drug dealer - "white boys, college-boy types, khaki pants" - whom they could easily intimidate and slap around.
"I was very loyal to the guys," he said. "I would lie for them. I would steal for them. I would abuse people for them. I wanted to be part of the squad."
Much of Walker's testimony corroborated stories told by the government witnesses that preceded him.
Describing a 2007 raid in which members of the field unit are accused of stealing $97,000 from drug dealer Robert Kushner's City Avenue apartment, Walker recalled a moment that Kushner described in detail during his own time on the stand.
Soon after entering the apartment, Liciardello spotted a photo on Kushner's wall of mobster John Gotti, the Gambino crime family's "Teflon Don."
Walker recalled Liciardello's calling Kushner in jail to say: "You ain't no gangster."
In describing other incidents, however, Walker occasionally contradicted previous testimony.
Earlier Tuesday, Howard Wilson told jurors that in 2006, Liciardello and others took $38,000 in drug money his nephew had stashed in a backpack hidden in his basement clothes dryer.
In Walker's retelling, the money was found in a Timberland shoe box stuffed into the appliance.
And though he explained his testimony as a way to help himself in his own case, McCartney's questioning revealed another possible motive for Walker's extensive cooperation - a bitter feud with Liciardello.
By 2009, Walker said, he felt himself being squeezed out of the squad.
First, the others refused to work with him, and he was partnered with Norman. Once Norman left the squad, Walker spent most days patrolling the streets by himself - a violation of police policy.
He became the target of cruel jokes. They teased him about his messy divorce and took photos of him when he fell asleep on surveillance jobs. After he underwent gastric bypass surgery, they called him names such as "Staple Stomach" and "Zip Mouth."
That tension came to a head in 2013, Walker said, when Internal Affairs investigators began investigating a complaint from a city prosecutor about Liciardello's behavior in court. Walker, who had testified in the same case, was called in to answer questions.
Normally, when one of the squad's members was brought before Internal Affairs, a supervisor would call in a favor and get a heads-up about the complaint so squad members could work out a believable cover story, Walker said.
This time, Walker didn't wait for that meeting. He told investigators that Liciardello and the rest were dirty, but didn't share details.
Somehow Liciardello found out, Walker testified, and that night unleashed his wrath. In a series of text messages shared with jurors, Liciardello berated Walker for the betrayal.
"You are dead to everyone in this squad," Liciardello wrote. "The problem you have is you're now a rat. I hope you die."
Despite their falling out, there were still times Walker felt desperate to win back Liciardello's trust, he said.
He told jurors he once lied in court about a drug buy to cover one of Liciardello's mistakes.
Asked by McCartney, the prosecutor, whether he ever stopped to think about how his false testimony affected the men his lies sent to jail, Walker responded: "I didn't think of them as being humans. They were criminals. It never crossed my mind."
When did you start to think differently, McCartney asked.
Walker replied: "Since being in jail myself."
Walker will return to the stand Wednesday to face what is expected to be a highly charged cross-examination.