ALBANY — District Attorney David Soares' office — which stoked controversy when it announced it would not prosecute peaceful Occupy Albany protesters last year — could be held in contempt of court if it doesn't move ahead with a case against a protester arrested in June, a city judge ruled Monday.

Judge William Carter's 12-page decision states Soares' office cannot "simply walk away" from the case against Colin Donnaruma without citing one of a handful of acceptable reasons listed in the state's criminal procedure law.

Carter's decision could be read to conflict with one rendered earlier this year by a fellow judge involving cases against 88 other Occupy protesters arrested in connection with their two-month encampment last year in city-owned Academy Park.

That decision by city Judge Thomas Keefe held that the court had no choice but to dismiss the charges against the occupiers because Soares would not prosecute them.

Citing Soares' similar refusal to prosecute Donnaruma, his defense lawyer argued the court "has no authority to do anything except to dismiss the case."

"This court disagrees," Carter responded, "and to the extent that (Keefe's ruling) holds otherwise, this court respectfully declines to follow that decision."

In his ruling, Carter cites precedent from a midlevel state appellate court that holds a prosecutor "does not possess unfettered discretion" and "may not simply walk away from the case and abandon it."

In fact, Carter writes, Soares' office exercised its discretion in the case when it began the prosecution on June 14, the day after Donnaruma, of Voorheesville, and three other protesters were arrested when police said they blocked traffic on Lark Street and refused orders to get on the sidewalk. Only later, in October, did Soares' office notify the court that it would not prosecute Donnaruma.

That could be a key distinction between his case and the earlier ones covered by Keefe's decision, in which prosecutors announced their intention to seek dismissal at the very first court appearances.

Donnaruma — one of the most visible members of the local Occupy movement — was charged with misdemeanor resisting arrest and disorderly conduct, a violation.

Soares' wielding of prosecutorial discretion not to prosecute peaceful protesters he deemed to be exercising their First Amendment right to free speech made him an early hero of the local Occupy movement.

It also is believed to have weighed heavily on the initial decision by city officials not to try to force the protesters from the park for violating its evening curfew, a move said to have strained relations between Mayor Jerry Jennings and Gov. Andrew Cuomo, whose administration sent word to city officials that it wanted the park across Washington Avenue from the Capitol cleared.

Only when the protesters began defying the curfew in the adjacent state-owned Lafayette Park did State Police begin to arrest them, triggering the raft of charges later dismissed by Keefe.

Others, however, were sharply critical of Soares' decision not to pursue the cases, arguing he was professionally and ethically obligated to enforce the law.

In order to terminate the case, the judge's decision states, he must be provided with one of the legally accepted reasons in state law, which range from the specific, such as a problem with jurisdiction or lack of a speedy trial, to the vague, such as "the furtherance of justice."

Carter also notes that Soares' refusal to heed the order would not be without consequences.

"Given that the District Attorney's October 4, 2012 letter stating that his office declines to prosecute these charges and 'will not be participating in motion practice or future proceedings,' the court is constrained to note that, should the Office of the District Attorney fail to appear at the next scheduled court date, this Court may be forced to utilize one of the few available options left to it under these circumstances, including, but not limited to, its contempt powers."

Carter — like Keefe and Soares — is a Democrat who was re-elected this month. Neither Carter nor Keefe faced opposition in their elections.

Soares, however, was criticized by his primary opponent, Lee Kindlon, for his blanket decision not to prosecute Occupy cases not involving violence, saying he would have left that for the courts to decide.

The district attorney has prosecuted at least one protester who was involved in the Dec. 22 scrum with police that ended their Academy Park encampment. That man, William Preston, pleaded guilty in February to disorderly conduct for blocking city workers who were trying to dismantle the protesters' last tent.

Soares pursued that case, he said, because Preston's actions that day "crossed the line from a peaceful protest into something else and caused a threat to others."

In a statement issued on Monday, Soares' spokeswoman, Cecilia Logue, said the "office respectfully disagrees with Judge Carter's decision."

"We have been present for all court dates pertaining to this matter and will continue to be present at future appearances," she said.

jcarleo-evangelist@timesunion.com • 518-454-5445 • @JCEvangelist_TU