A female teacher and an 8-year-old student were fatally shot and another student was critically injured in an apparent murder-suicide Monday morning at a California elementary school, according to police.

The suspected gunman – who was the teacher’s husband – shot and killed himself, police said.

The shooting was first reported at 10:27 a.m. local time at North Park Elementary School in San Bernardino, California. Police later identified the shooter as 53-year-old Cedric Anderson. His wife was identified as Karen Elaine, also 53.

Police said the shooting occurred in a multi-grade special education classroom with students from first to fourth grade. There were also two adult aids and 15 students present.

The slain student was named as Jonathan Martinez, police said Monday afternoon. The second student, a 9-year-old boy, was hospitalized locally and was in stable condition.

Police said the two students who were shot were not targeted and were instead hit “because of their proximity to the victim.”

“[The shooter] entered the classroom – and without saying anything, and armed with a large caliber revolver, he shot his wife,” San Bernardino Police Chief Jarrod Burguan said at a Monday afternoon news conference.

What precipitated the shooting was not immediately clear, though police said Anderson has a history of domestic violence.

He was armed with a .357 revolver, they said.

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There was is “no indication the gun was visible” before the shooting, San Bernardino police Capt. Ron Maass said.

“It wasn’t until [the shooter] came into the classroom that he presented the weapon,” Maass said.

The school is not equipped with metal detectors, district spokeswoman Maria Garcia tells PEOPLE.

“When he [the shooter] entered the school, he entered the school from the front office and no one felt uncomfortably or said he shouldn’t be allowed in,” she says. “He followed the procedures.”