(CN) - A former Massachusetts federal prosecutor cannot preside over the trial of notorious mob boss James "Whitey" Bulger, because a reasonable person might doubt his impartiality, the 1st Circuit ruled Thursday.
The opinion was written by former U.S. Supreme Court Justice David Souter, who serves as an associate justice on the 1st Circuit for three months of the year.
Bulger, 83, the former leader of the Winter Hill Gang in Boston, is charged with 19 murders spanning over a decade, as well as racketeering, extortion and drug trafficking. During this period, he also worked as an FBI informant and now claims that a federal prosecutor granted him immunity for his crimes in return for his assistance.
A long-time presence on the FBI's Top 10 Most Wanted Fugitive list, Bulger eluded arrest for 16 years living quietly in Santa Monica, Calif., before he was arrested in June 2011.
The government's case against Bulger was randomly assigned to U.S. District Judge Richard Stearns, who formerly worked as an assistant U.S. attorney during the period that Bulger was an informant.
Bulger asked Stearns to recuse himself based on his former position in the U.S. attorney's office, arguing that it would be difficult for Stearns to remain impartial, especially when he would likely have personal relationships with numerous witnesses.
However, Stearns rejected any question of his impartiality.
"It would be institutionally irresponsible for me, or for that matter, any other judge, to enter a recusal in a case where a party has chosen to make untrue accusations in the possible hope of subverting that process, or at the very least, forcing a delay of a trial by injecting a diversionary issue into the proceedings," he wrote.
"I am confident that no reasonable person could doubt my impartiality."
In reversing Stearns' decision, the federal appeals panel in Boston did not question his impartiality but said a reasonable person might raise the question of bias.
"Given the institutional ties described here, the reasonable person might well question whether a judge who bore supervisory responsibility for prosecutorial activities during some of the time at issue could suppress his inevitable feelings and remain impartial when asked to determine how far to delve into the relationship between defendant and government, and to preside over whatever enquiry may ultimately be conducted," Souter wrote.
The court said its decision was not based on a question of harm to the defendant, but on damage to the judicial system.
"It is enough to say that we need not consider a rule that a clear showing under the substantive recusal standard always suffices to demonstrate irreparable harm, for here the prior disclosures make it imperative to act promptly to preclude any reasonable question whether untoward government action in the past may affect the fairness of the judicial branch in the present," Souter wrote.
"Despite our respect for Judge Stearns and our belief in his sincerity, we are nonetheless bound to conclude that it is clear that a reasonable person might question the judge's ability to preserve impartiality through the course of this prosecution and the likely rulings made necessary by the immunity claim."