(CNN) -- The principal of an elementary school in Northern California was shot to death Wednesday, police said.

Placerville Police Chief George Nielsen identified the victim as Sam Lacara, 50, the principal of Schnell School. He was shot in the upper torso.

John Luebbers, 44, a custodial employee, was arrested in the shooting, which was believed to have stemmed from a dispute between the two men, Nielsen said.

No schoolchildren were injured, but authorities believe one student may have seen the shooting.

Authorities received a 911 call midmorning Wednesday that shots had been fired at the school, Nielsen said.

"It's a tragedy for Placerville and for our entire society," Nielsen said.

"The main issue with how to deal with students was the ongoing investigation and the crime scene," he said, "and ultimately that was to remove them (to a nearby fairground) and get them back to their families."

Placerville is in Northern California, 45 miles east of Sacramento.

From CNN's Amanda Watts