A fight over a mask at a high school basketball game may have played a role in the death of a police officer Friday night.

The police officer working security at the game in New Orleans was shot in the chest by a man who was denied entry into the game, authorities said.

NOLA.com reports that John Shallerhorn, 35,  had just been embroiled in an argument with a school staffer about the school’s mask mandate and other coronavirus restrictions before shooting the officer, later identified as Tulane University Police Cpl. Martinus Mitchum.

Mitchum reportedly went to intervene after Shallerhorn refused to wear a mask. That is when Shallerhorn reportedly shot Mitchim.

The shots were fired Friday evening near the gymnasium at George Washington Carver High School, Police Superintendent Shaun Ferguson told reporters at a news conference.

Two loud bangs were captured on video shared by WGNO-TV as the high schoolers played. A photographer from WWL-TV also reported that the gunfire could be heard inside the gym.

The school was put on lockdown after the shooting, news outlets reported, and the game was ultimately called off.

Mitchum, who also was a deputy constable with the Second City Court, later died at a hospital.

Shallerhorn was arrested and charged with first-degree murder of a policeman. He’s also charged with armed robbery since he was accused of robbing a man at gunpoint in the parking lot prior to the shooting, WVUE-TV reported. It was unknown if he has an attorney who could speak on his behalf.

Tulane University Police Chief Kirk Bouyelas issued a statement Saturday in which he mourned Mitchum’s death.

“We are deeply saddened by the senseless and tragic death of TUPD Corporal Martinus Mitchum. Corporal Mitchum was a dedicated police professional who had a heart of service for the Tulane community,” Bouyelas said.

Bouyelas said they are providing support to Mitchum’s family and fellow officers.

“Our thoughts and prayers are with his family and with all the fellow officers with whom he served,” he said.

The fallen officer had been “a fixture at Carver sporting events and parades” according to a statement from the high school. “All spectators, families, and players are safe — a testament (to) the officer, outside security support, school staff, and systems in place.”

The school also said it would offer resources to anyone in the Carver community who needed support in the wake of the shooting.

Just moments before Shallerhorn attempted to enter the school, authorities said he robbed a man at gunpoint in the parking lot. Police said a 39-year-old man was sitting inside his vehicle when he was approached by the suspect.

Shallerhorn raised his shirt and brandished a gun while demanding the victim’s medallion chain, police said. The victim complied.