By ANDY GARDNER

POTSDAM -- State police have completed their investigation into the September fatal police shooting of a Clarkson grad student in which another Clarkson pupil was also killed.

It is now in the hands of the District Attorney’s Office, according to Potsdam Police Chief Kevin Bates.

“The last I heard, and this was back in November or December, it had been passed to the DA from state police and it was going to go to grand jury and I haven’t heard anything about it since,” Bates said.

District Attorney Mary Rain did not return a request for comment.

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 while stabbing Yazhen Jiang, 25, and threatened the officer, police said. The incident took place Sept. 10 at the Swan Landing apartments.

Bates said he isn’t sure of a motive.

“That’s in the state police file that … I did not get a chance to see,” Bates said. “I wasn’t even given access to the state police file.”

Bureau of Criminal Investigation Capt. Robert LaFountain said the autopsy report of Ma and Jiang showed “nothing remarkable.”

Seymour has since returned to full duty. The DA’s Office is holding as evidence his weapon and duty belt from the day of the incident. The department has provided Seymour with a new weapon, holster, handcuffs and other necessities.

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

Potsdam officers Seymour and Clint Perrigo were sent to investigate calls for help from neighbors who called police about 2:45 p.m. Sept. 10 after hearing screams at Swan Landing.

The officers found Ma on top of Jiang, stabbing her, police said at the time. 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 at the time said her office will present evidence in the case to a grand jury soon as a matter of procedure.

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 in September 2015.

At that time, she 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 last year.