By CRAIG FREILICH

POTSDAM -- The Potsdam police officer who shot and killed a man found stabbing a woman to death Thursday is on leave while the investigation continues, according to village police.

Patrolman Matthew Seymour shot his Glock 21 .45 caliber pistol four times after Tian Ma, 31, a Clarkson University graduate student from China, refused to drop his knife and threatened the officer, police said.

St. Lawrence County District Attorney Mary Rain said her office is compiling evidence in the deaths at the Swan Landing apartment complex to present to a grand jury, which will be asked to determine if the shooting was proper.

Rain said it is “standard practice to present to a grand jury” evidence in an officer-involved shooting. “We want to ensure the public the police did everything properly,” Rain said.

As of Monday afternoon, there had been no public report on the autopsies of Ma or his female victim, Yazhen Jiang, 25, that were to be performed by Dr. Michael Sikirica at Albany Medical Center. Jiang was also a Chinese national attending Clarkson.

Police said Ma had returned to the United States from China on Wednesday, Sept. 9, and arrived in Potsdam by bus on Thursday morning.

Potsdam officers Seymour and Clint Perrigo were sent to investigate calls for help from neighbors who called police about 2:45 p.m. after hearing screams at Swan Landing.

The officers found Ma on top of Jiang, stabbing her, police said. When Ma refused to drop his knife and threatened the officers, Seymour fired the four shots, hitting and killing the man, police said.

Jiang was taken to Canton-Potsdam Hospital and was pronounced dead.

DA Rain said her office will present evidence in the case to a grand jury soon as a matter of procedure.

Officer Seymour is an 11-year veteran of the Potsdam Police Department, a firearms instructor and a certified emergency medical technician.

Seymour has told the DA’s office that he will testify at the grand jury, Rain said.

Rain said she will present state police and medical examiner’s findings for an independent review by the grand jury of the shooting “to provide transparency to the public that the officer’s actions were justifiable. Officer Seymour and Officer Perrigo fully cooperated with the investigation in this matter,” she said.

So far there has been no news from investigators about the relationship between the two students, both originally from China, or any possible motive for the stabbing. Both aspects of the case remain under investigation, according to state police on Monday.

Asked if anyone can remember a Potsdam police officer firing a weapon while on duty, Potsdam Police Chief Kevin Bates said, “Other than, you know, an injured deer, no, not to my knowledge. There is a rumor that it might have happened in the ’40s or ’50s,” but he hasn’t been able to confirm anything like that.

Bates said state police are handling most of the investigation with the resources at their disposal. He would not comment on any new results of the investigation, deferring to Bureau of Criminal Investigation personnel.

A senior BCI investigator said he could not comment and referred us to the public information officer in Troop B headquarters in Ray Brook, but no more information was forthcoming.