CLARKSBURG (CBS13) — A substitute teacher is banned from a Clarksburg elementary school after dozing off during his lesson plan. The bizarre behavior comes as more subs are spending time in California classrooms with schools stretched thin by COVID-19 staffing shortages.

“Teacher acting erratic enough to call the sheriff, it just makes me wonder,” explained parent Pete Beck.

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A substitute teacher at Delta Elementary Charter School was caught nodding in and out during class. His behavior prompted the school to go into a soft lockdown. As the man was removed from the classroom, the Yolo County Sheriff’s Office was called to investigate. Deputies determined the teacher was not under the influence.

“How are they vetting these people? How did this guy get in? I know it is a charter school but if it can happen here, it can happen anywhere,” said Beck.

Beck’s two daughters go to the school. His oldest, Sierra, is in sixth grade and has been taught by the substitute in the past.

“He wasn’t as experienced as our teacher or the other subs we had,” explained Sierra.

CBS13 asked how long the teacher had been a sub. According to the superintendent, the substitute was contracted by an agency as a short-term teacher who has only taught a couple of days this year. This comes as the state deals with a critical teacher shortage.

“When I was a kid, I had substitutes. I know they do a good job of bringing in good teachers,” explained parent Jason Stephen.

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While long-term substitutes undergo evaluations by the school, short-term teachers do not.

According to the state, the requirements for substitute teaching include a bachelor’s degree, a basic skills test and a background check with fingerprints.

The background check includes cross-checking information from the FBI and Department of Justice. Despite the background check, you can still be a sub in some cases even if you have a minor criminal record if the crime does not involve children.

“The realities of what schools are facing as just not having enough adult supervision in classrooms is putting a lot of stress on the system,” explained Troy Flint, spokesperson for California School Board Association

The sleepy substitute situation is putting Beck on alert hoping stricter policies come in the future.

“How do we weed these people out of the system?” he said.

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The substitute teacher will not be allowed back on the campus to teach.