MINNEAPOLIS — A judge on Monday found a Minnesota substitute teacher guilty of mistreating students at an elementary school, where authorities say she kicked a fifth-grade student in the shin and slapped another in the face.

Laura Avery, 60, was found guilty of four charges of malicious punishment of a child, the Star Tribune reported. She was acquitted on a charge of tampering with a witness. A sentencing date has not been set.

A home phone number for Avery could not be found. A phone message from The Associated Press left after hours for her attorney was not immediately returned Monday evening

According to the charges, a school employee found four students crying in the hallway on Dec. 13, 2012. The students said Avery swore at them and threatened to slap them if they didn’t do what she asked.

Prosecutors determined that Avery later took three students to a school “quiet” room, grabbing one student by the shoulder so hard that a school nurse observed redness on the boy. Another student told state investigators that Avery grabbed his neck and pushed him into the room.