WAUKESHA, WI (WTAQ) - A Waukesha man has been arrested for walking into North High School and threatening to kill his ex-girlfriend.

Eighteen year old Jordan Hartz had been expelled from the school and wasn’t allowed to return.

The 17 year old girl says she was sitting in English class when she heard someone pounding on the door.

When the teacher opened that door, the girl says she could see Hartz.

First, he tried to push his way in, then he ran away when more teachers arrived.

Hartz had been able to get in when another student let him in through a side door. He faces several charges, though no one was injured in the incident.