A substitute teacher in the St. Paul School District offered a lesson Tuesday on what not to do if you're looking for teaching jobs: Drink and teach at the same time.

The teacher was sent home after he was apparently drinking while teaching a fourth-grade class at Roosevelt Elementary West Side School of Excellence.

Police found a pint-size bottle of Phillips vodka in his bag and gave him a ride home after he registered 0.18 percent on a Breathalyzer test.

"The substitute was dismissed immediately," said Sharon Freeman, executive director of elementary education for the district. School district policy prohibits the use and/or possession of alcohol in schools.

A staff member at the school told Principal Scott Tryggeseth that the teacher was acting suspiciously, Freeman said. Tryggeseth called police at 1 p.m. after speaking to the teacher.

Fourth-grade parents received a letter from Tryggeseth on Tuesday that said the teacher "will not be returning to our or any other Saint Paul Public Schools building. As you know, providing a safe learning environment is our highest priority at Roosevelt and we are taking this allegation very seriously."

According to Freeman, the substitute had worked in the St. Paul public schools since September 2005, and no other schools had ever asked him not to return.

St. Paul school officials deferred details about the case to the police, who are investigating to determine whether a crime has been committed. "The last thing the school district wants to do is jeopardize a police investigation," said Howie Padilla, district spokesman. "Our job is to educate our students and to protect them. It's not up to educators to determine whether a crime has been committed."

Police spokesman Pete Crum said police will work with the city attorney's office to determine if a crime was committed. The teacher had taken the bus to school.

"This isn't something that happens very often," Crum said. "I'm not really sure what a charge would be, but clearly, I don't think he's going to have a job anymore."

Staff writer Mary Lynn Smith contributed to this report. Emily Johns • 612-673-7460