BERNE — The principal of Berne-Knox-Westerlo High School was placed on paid administrative leave Monday night by the school district's Board of Education after she was arrested over the weekend.

Mary L. Petrilli, 54, of Schodack, was arrested Saturday by state police after a domestic dispute in the front yard of her residence, troopers said.

A passerby noticed two people involved in a physical altercation and Petrilli allegedly had a 12 inch kitchen knife in her possession, troopers said. Troopers responded, and Petrilli, who has been on medical leave since October, was charged with second-degree menacing and fourth-degree criminal possession of a weapon.

The school board met in an emergency executive session Monday after it learned of Petrilli's arrest. District administrators said in a statement they are "obviously very dismayed by this report."

Petrilli will remain on paid leave, pending the outcome of a police investigation and internal investigation. While on leave, she is prohibited from returning to school grounds.

"As we prepare for the start of the 2008-2009 school year, we are committed to taking decisive action to secure full-time leadership at the high school," Superintendent Steven Schrade said Monday. "Accordingly, we plan to appoint an acting full-time administrator to serve for as long as necessary until this situation is resolved."