In the social media posts, the teacher, who the school district has not identified, is heard criticizing U.S. Immigration policy, asking students how long they have been living in the country, and polling the students to see who had been in the U.S. the least amount of time.
According to Fresno Unified, the substitute also asked students about their immigration status and resident cards, which they called "inappropriate and unacceptable."
Roosevelt High, where this incident allegedly took place, has a population of more than 82% Hispanic or Latino students, which is the highest percentage of any high school in the district.
A mother, whose son attends Roosevelt, said this isn't the first time this teacher has made these types of comments.
She asked to speak anonymously because her son is still a student at the school.
"He was teaching and talking about Mexicans and suddenly my son took out his phone a little bit to watch the timing," said the mother.
"And that's when he said clearly Mexicans are like criminals, exactly like my son, he named him."
She says she sends her kids to school hoping they're in a safe environment and even though she's disturbed by the statements she encouraged her son to take the high road.
"Just walk away, just walk away, it's not worth it, it's not worth it. And he had told me you're right Mom, I'll try, but just remember I have feelings."
She said it was disheartening to see this happen again after she addressed it with the school last year.
She's hopeful this audio of the latest incident will push the district to keep the substitute out of the classroom.
Fresno Unified released a statement that said:
"Questioning students about their immigration status is not aligned with our district's values or policies, and we want to be clear this is not acceptable in any of our classrooms."
That policy has been reiterated several times recently in social media posts.
"It is crucial that you know we will never ask for immigration information about your student or your family."
This audio comes as tensions are high across the country regarding the Trump administration's immigration policies.
Friday afternoon, Fresno Unified students took part in a walk-out in protest, a large group outside of Duncan Polytech High School could be seen holding flags and posters.
Fresno Unified School District released a statement saying they notified parents, their safety team, and the Fresno police department.
The district said several administrators were out with the students to ensure their safety during the protest.
Action News reached out to the substitute but has not heard back.
The school district said HR is handling the situation but has not said if the substitute is still employed by the district.
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