MUSKEGO, Wis. (CBS 58) -- A substitute teacher is facing charges, accused of going to work at an elementary school while under the influence. 

The 30-year-old man is now facing his fourth OWI charge. 

According to a criminal complaint, Christopher Rias was working as a substitute physical education teacher at Bay Lane Elementary School in Muskego when the incident occurred. 

A letter to families says he was removed from a classroom on Oct. 30. Police say he took a breath test and blew a .36. 

A school resource officer reviewed surveillance footage, according to the complaint, which reportedly showed Rias driving his vehicle to school and exhibiting poor balance, almost falling while entering the building.

Prosecutors say Rias also had an active arrest warrant for failing to appear on an OWI third offense.

He is due in court on Nov. 13.