The district attorney's office said it is proactively taking steps to identify all department cases involving Rick Fitzgerald.
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Fitzgerald's attorney says he left the Proud Boys group a few months ago over disagreements.
In a statement, DA Smittcamp said, "It's important that every citizen in the County of Fresno trust that members of our law enforcement community will behave equitably and free from biases when investigating, evaluating and prosecuting cases."
The police department put Fitzgerald on paid leave and is conducting an internal investigation.
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