May 10—POTSDAM — The arraignment of a former village police officer charged with choking a suspect has been postponed.

Matthew A. Seymour, 45, is facing one misdemeanor count of criminal obstruction of breathing.

He was scheduled to be arraigned on the charge Wednesday afternoon in Potsdam Town Court. Court officials said there was no judge available to preside. They said there is no new date scheduled yet.

Seymour was arrested after an April 1 incident where he "applied pressure to the throat of a male individual (in custody) which impeded his breathing," according to the St. Lawrence County Sheriff's Office, which investigated and made the arrest.

The sheriff's office said it started its investigation after receiving "a referral from the Potsdam Village Police Department through the St. Lawrence County District Attorney's Office in regards to an incident involving an on duty patrolman."

The St. Lawrence County district attorney is requesting a special prosecutor from outside the county to try the case.

Earlier this month, District Attorney Gary M. Pasqua said he's filed an application with County Court Judge Gregory P. Storie to appoint an outside prosecutor. It will be up to the judge to find and appoint that person.

The DA says there are two reasons they need the special prosecutor.

"We have open cases with the victim ... we're still prosecuting," Mr. Pasqua said. "Because Mr. Seymour is a former police officer my office worked with for a long time, we don't want there to be any reason of impropriety."

He declined to name the victim in the strangulation case.

"We never give out the names of victims in any case," the DA said.

In 2015, Seymour was placed on leave after shooting and killing a Clarkson University graduate student found stabbing a classmate in the grad student's apartment.

Seymour returned to the department on Nov. 3, 2015, after he was placed on paid administrative leave Sept. 10, the day that he fired four shots from his .45-caliber Glock 21 service pistol, killing 31-year-old Tian Ma.

Seymour and officer Clinton M. Perrigo arrived at 401 Swan St. in the Swan Landing Apartments in response to a report of a domestic assault, and found Ma on top of 25-year-old Yazhen Jiang, stabbing both her and himself. Mr. Perrigo did not fire his pistol.

At the time of the shooting, then-village police chief Kevin M. Bates said Ma refused to obey the officers' commands to drop the knife.

"They had their weapons drawn and asked the assailant several times to drop the knife and he did not comply," Mr. Bates said in 2015. "Officer Seymour shot four times, killing Ma on the spot."

Seymour afterward agreed to testify before a grand jury that reviewed the shooting to make sure it was either in self-defense or in protection of a third party.

Then-village administrator Everett E. Basford in November 2015 said he and Mr. Bates made the decision to have Seymour return to work following a discussion they had a week prior, without the grand jury having convened.

"There was no requirement that he be put off work. It is precautionary to remove someone involved in a fatality," Mr. Basford said in 2015. "At this point we have been assured that there were no pending issues to be aware of, so we thought it was time to bring him back."

"It would have been nice if the grand jury convened and confirmed that it was an unfortunate but justified action and that there were no circumstances that would have prohibited him from returning to work," Mr. Basford said at the time.