After defense attorneys in the college admission cases accused Boston prosecutors of “judge-shopping,” the chief federal judge in Massachusetts on Thursday rejected the defense attorneys' request to intervene.

Defense lawyers for parents, of whom 16 were indicted Tuesday on charges of money laundering and fraud conspiracy, told U.S. District Chief Judge Patti Saris earlier this week that the U.S. attorney for the District of Massachusetts was trying to get around court rules. Andrew Lelling, the U.S. attorney in Boston, denied the accusation and said it was the defense that sought to bend the rules for its benefit.

Judge Nathaniel Gorton.

The defense team said that by issuing a superseding indictment in the case of a parent whose case had already been assigned to U.S. District Judge Nathaniel Gorton, prosecutors avoided the random judge-assignment process that is supposed to occur with new cases. But Lelling wrote that a superseding indictment to add co-conspirators was “routine.”

In a one-page letter Thursday to defense lawyers, Saris said her court was committed to ensuring “integrity and fairness” in the case-assignment process. But she indicated that she would not step into the fray.

“Your claim that the defendants have been improperly joined must be addressed to the presiding judge,” Saris wrote, referring to Gorton. “If he severs any defendant(s), the presiding judge has the authority to return the indictment of that defendant for random re-assignment.”

In their letter to Saris on Tuesday, the defense lawyers said they had no problem with Gorton. But Lelling, in his letter to Saris on the same day, said the defense attorneys likely wanted a different judge because they believe Gorton imposes longer sentences compared with others in the district.

Harvey Silverglate, a Boston defense lawyer known for his civil liberties work who is not involved with the case, told ALM in an email that Gorton is regarded as “a pro-prosecution judge and a tough sentencer.”

Silverglate, of counsel at Zalkind Duncan & Bernstein, said because “Gorton is so tough and pro-prosecution,” he believes the judge is unlikely to rule that the newly added defendants be re-indicted and their cases re-assigned by random selection. “This is probably why the lawyers have complained not to Gorton (deaf ears) but rather to the chief judge,” Silverglate said.

Defense attorneys who signed the letter to Saris include those from Mintz, Levin, Cohn, Ferris, Glovsky and Popeo; Bienert Katzman; Orrick, Herrington & Sutcliffe; Keller/Anderle; Ropes & Gray; Nixon Peabody; White & Case; Nutter McClennen & Fish; Todd & Weld; Miner Orkand Siddall; Boies Schiller Flexner; Duane Morris; and the solo practitioner Martin Weinberg.

Arraignment dates have not been scheduled for the indicted parents.