Counterprotesters, including one wearing a horse mask, line the route of the Straight Pride Parade in Boston, Saturday, Aug. 31, 2019. (AP Photo/Michael Dwyer)

BOSTON (AP) — Boston's district attorney has asked Massachusetts' highest court to intervene in a dispute with a lower court judge over the arrest of counterprotesters during a "straight pride" parade in Boston over Labor Day weekend.

Suffolk County District Attorney Rachael Rollins filed an emergency petition Wednesday asking the state's Supreme Judicial Court to compel the lower court to accept her request not to prosecute at least one counterprotester charged with disorderly conduct following Saturday's parade , which was meant to be a counterpoint to gay pride parades and drew a few hundred participants but hundreds more counterprotesters.

Rollins argued that Boston Municipal Court Judge Richard Sinnott overstepped his constitutional authority in refusing to recognize her office's request.

"In so doing, the judge ignored the clear and unambiguous constraints placed on the judiciary" by the Massachusetts Declaration of Rights, Rollins wrote.

The filing of a "nolle prosequi" by her office, she said, is a "constitutionally protected action that affords the prosecutor the right to exercise her judgment in the prosecution of cases and the allocation of limited prosecutorial resources to protect public safety."

Court spokespersons representing Sinnott and the high court didn't respond to an email seeking comment late Wednesday night.

While the emergency petition focuses on a single case, Rollins hopes it sets a precedent that will benefit other counterprotesters facing similar minor charges.

"The power to pursue prosecution falls exclusively on the executive branch, not the judiciary," she said in a statement. "My petition is a call for order to be returned to our courts, to ensure the fair administration of justice, and to restore the public's trust in the integrity of our legal system."

The dispute between Rollins and Sinnott began Tuesday when the judge denied her request to dismiss charges in at least seven of the 36 cases stemming from the parade.

Rollins promised she'd take other steps to get the charges dropped.

Then on Wednesday, Sinnott held defense lawyer Susan Church in contempt after he denied Rollins' office request to drop charges against her client, who was a counterprotester.

Sinnott had Church handcuffed and detained for about two hours because she began reading from case law suggesting he had no authority to overrule Rollins' decision not to prosecute the case.

A labor union representing Boston police officers, meanwhile, cheered Sinnott's hardline stance.

The Boston Police Patrolmen's Association had called for the prosecutions of everyone arrested at the parade after, it says, officers were pelted with rocks, bottles of urine and other unidentified materials as the parade wound down, injuring at least four officers.

"We think that these offenders, most of them not residents of Boston, came here as agitators," Lawrence Calderone, the union's vice president told The Boston Globe on Tuesday. They came here to "create havoc," he said.

Mayor Marty Walsh has said the police department is also looking into complaints of police misconduct, including the use of pepper spray on counterprotesters.

The court spat is the latest tussle between Rollins, whose office handles prosecutions in Boston and some surrounding communities, and the state's judicial and law enforcement establishment.

Shortly after being elected in November, Rollins, a Democrat, listed 15 nonviolent offenses her office would no longer prosecute, including drug possession, shoplifting and trespassing.

The memo drew criticism from Republican Gov. Charlie Baker's administration, which said the approach could undermine efforts to address the national opioid epidemic and put some crime victims at risk.

Rollins also joined advocates for immigrants and another Massachusetts district attorney in successfully suing to prevent federal immigration agents from carrying out civil arrests in state courthouses.

While her office has moved to drop charges against some of Saturday's protesters, Rollins is still pursuing charges against those facing more serious offenses.

Among them were three men arraigned Tuesday on charges of assault and battery on a police officer. The men were ordered by a judge not to set foot again in Boston except for required court appearances, or else face jail time.

"Make no mistake: some people were appropriately arraigned and will be held accountable for actions that put the safety of the public and law enforcement at risk," Rollins said Tuesday.

A marcher wears a dinosaur costume during the Straight Pride Parade in Boston, Saturday, Aug. 31, 2019. Several dozen marchers and about as many counter-demonstrators have gathered in Boston for a