One Traffic Court judge expected to be charged is already under indictment for a separate accusation. Robert Mulgrew was indicted by a federal grand jury in September, accused of misusing hundreds of thousands of dollars in state grants meant for nonprofit groups in South Philly.
The state Supreme Court in September suspended Mulgrew, whose wife was also charged along with Lorraine DiSpaldo, chief of staff to state Rep. Bill Keller.
Mulgrew's attorney, Angie Halim, declined to comment.
Attorney William Brennan, who represents former Traffic Judge Willie Singletary, another target of the federal investigation, also declined to comment.
Singletary resigned from his seat last March in an unrelated matter: A female Traffic Court cashier had accused him of showing her pictures of his erect penis in December 2011.
Judge Christine Solomon's attorney, Samuel Stretton, said that she had not received a target letter from federal prosecutors.
Stretton added that "I do hear a lot's going to happen" with the Traffic Court case Thursday.
Solomon may be spared because, as the newest judge on the court, she did not start hearing cases until last March.
Solomon, a ward leader for two decades, previously refused to cooperate with a state Supreme Court-commissioned investigation into Traffic Court practices.
State Chief Justice Ron Castille launched that inquiry in December 2011, three months after FBI agents raided the homes and offices of Traffic Court officials.
Castille also removed Michael Sullivan as the court's administrative judge in that action.
Sullivan's attorney did not respond to a request for comment.
Lynanne Wescott, attorney for former Traffic Court Administrative Judge Bernice DeAngelis, said that she was unaware of impending Traffic Court indictments.
DeAngelis had been serving as a senior judge until being dismissed from service by the state Supreme Court in April.
The 2011 FBI raids included search warrants served at homes and offices of Sullivan and the Traffic Court's then-director of operations, Bill Hird, as well as at two bars that Sullivan and Hird ran.
Hird did not respond to a request for comment Wednesday.
FBI agents also raided the home of Senior Judge Fortunato Perri Sr., a onetime administrative judge for the court. Perri could not be reached by phone Wednesday. A message left for his son, defense attorney Fortunato Perri Jr., was not returned.
Chadwick Associates, a consulting firm hired by Castille, reported in November that Traffic Court had a "two-track system of justice, one for the politically connected and another for the unwitting general public."
H. Warren Hogeland, a Bucks County senior district judge who heard cases in Philadelphia Traffic Court, told the firm that DeAngelis ordered him to grant political favors in cases when she was administrative judge in 2005.
Judge Michael Lowry, the son of a former ward leader, admitted to special treatment for the politically connected and "implicated other judges," the firm reported.
Lowry did not respond to a request for comment Wednesday.
The report described an informal system of requests for special treatment handed to judges on index cards that were tossed in the trash after trial.
Special treatment ranged from downgrading of traffic charges to outright acquittals to the most valuable political perk: A "not guilty in absentia" verdict, which meant the defendant didn't even have to show up in court.
The report said that 22 Traffic Court employees called special treatment common and 19 of them "could not identify a single judge who did not participate."
And the report described an "intensely political environment" where jobs depended on connections and partisan allegiance.
Election to Traffic Court, where judges don't have to be attorneys and are paid $91,052, depends on political connections as well.