But court filings and Internal Affairs reports obtained by The Inquirer suggest that on at least three occasions, some of the indicted officers have been accused of exactly that.
The documents show that two former drug suspects arrested by the group - and their lawyer - lodged complaints in 2005 that the narcotics officers retaliated against them over lawsuits filed in federal court.
In one case, Andre Blaylock, a West Philadelphia drug suspect who sued over his 2003 arrest, told a judge that one of the officers followed him home and "used his hand to point an imaginary gun and fired at me."
Whether those allegations alone - some of which were deemed unsubstantiated by Internal Affairs - would have swayed Robreno's decision Thursday remains uncertain.
But the allegations seem to buttress prosecutors' fears on behalf of the witnesses set to testify against the officers in their current criminal case.
"Quite frankly, this is a real concern for the government," prosecutor Anthony Wzorek said in court Thursday. "Witnesses have expressed concern to us about what's going to happen to them with the Police Department."
FBI agents arrested Officers Brian Reynolds, Thomas Liciardello, and four of their former colleagues last week on charges including conspiracy, robbery, and extortion.
Prosecutors say the group carried out a six-year reign of terror on South Philadelphia streets, beating and robbing drug suspects while confident that no one would believe the word of any who spoke out against them.
In court Monday, Wzorek urged U.S. Magistrate Judge Timothy Rice to hold all of the officers in custody until their trial, saying he feared that the group posed a danger to government witnesses.
Rice agreed to keep Liciardello, the group's purported ringleader, behind bars, but rebuffed the prosecution request when it came to four of the other officers. Without specific evidence to justify Wzorek's fears, he had no reason to keep them behind bars, Rice said in an opinion released Wednesday.
Prosecutors appealed, but Robreno affirmed Rice's decision Thursday. He added restrictions on the officers' house arrest, barring them from communicating with any current or former police officers.
"What are the facts that suggest he will be an ongoing danger to the community?" the judge asked Wzorek during a hearing for Reynolds. "There must be some evidence other than the assertion that the defendant might possibly threaten a witness."
Civil rights lawyer Michael Pileggi sought to bring just such evidence to the attention of authorities in 2005.
According to an Internal Affairs report from that year, the lawyer accused Reynolds, Liciardello, and a third officer, Jeffrey Walker, of "arresting several of his witnesses that were scheduled to appear in a pending federal trial, allegedly for retaliatory and/or harassment purposes."
(Walker pleaded guilty to robbery and gun charges in a separate federal case this year and has since become one of the government's chief witnesses against his former colleagues.)
Internal Affairs investigators ultimately found Pileggi's complaint unsubstantiated, saying the lawyer did not respond to efforts to contact him about his allegations.
Reached Thursday afternoon, Pileggi declined to comment, citing his involvement in ongoing lawsuits against the officers.
During the last decade, Pileggi has become one of the narcotics officers' chief critics, filing dozens of wrongful-arrest suits on behalf of drug suspects who say the investigators fabricated evidence against them.
The officers, in turn, have accused him in a lawsuit filed in 2006 of bringing frivolous actions against them that falsely portrayed them as liars and thieves.
In a letter to the Police Department, a lawyer for Pileggi also said the squad had begun harassing and threatening Pileggi's law clients and telling people he would be disbarred. At one point, the letter said, Liciardello showed up at his office uninvited and fired questions at him about his marriage and family. He told Pileggi he was "investigating" him, the letter said.
Blaylock, one of Pileggi's clients, also raised the specter of retaliation during a June 2005 hearing before U.S. District Judge Norma Shapiro.
Earlier that year, he had sued Reynolds, Liciardello, Walker, and other officers, alleging they had wrongfully arrested and then beaten him in 2003. A month after the suit was filed, he told Shapiro, Liciardello, and Walker arrived at his home in an unmarked vehicle.
"Officer Walker used his hand to point an imaginary gun and fired at me," Blaylock said in an affidavit. Before speeding off, he said, Walker cursed at him.
The city later paid Blaylock $47,500 to settle his lawsuit.
At the same time that Blaylock lodged his intimidation accusations, Samuel Dupriest - another former Pileggi client who settled a 2004 false-arrest case against the officers for $95,000 - said in an affidavit that officers approached him outside his daughter's school and warned, "You'll be getting locked up real soon."
Liciardello and Walker denied both men's accusations at the time, saying they could prove that they were in another part of the city when the alleged harassment occurred.
But it was another incident, cited by prosecutors, that led Rice to order Liciardello held in federal custody Monday.
In the only example of witness intimidation that prosecutors provided during bail hearings this week, Wzorek accused the 38-year-old of following the wife of a man he allegedly kidnapped in 2006 and later calling her to let her know that he noticed she had dyed her hair.
As for Reynolds, who was released on bond Thursday, his lawyer Jack McMahon addressed the prosecution's concerns in no uncertain terms:
"We all have concern for the witnesses," he said. "There is no history on Brian Reynolds of threatening witnesses."