FULLERTON (CBSLA) — Many are wondering why Fullerton Police Chief David Hendricks and one of his captains, Thomas Oliveras, were forced to take a leave of absence.

CBSLA has learned that Hendricks is the subject of a criminal investigation. The charge is attacking a paramedic.

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Sources tell CBSLA that Hendricks and Oliveras attended a concert Friday night and then got into a brawl with two paramedics.

The Fullerton city manager wrote in a cryptic email:

“At my direction, Chief of Police David Hendricks and another officer have been placed on paid administrative leave pending the outcome of an ongoing investigation. This investigation is unconnected to the performance of official duties, as it relates to allegations of off-duty conduct outside of the City. The City does not intend to provide further details or comments regarding this matter.”

But in a letter to the Irvine mayor and city council, the Irvine police chief confirmed Irvine police were conducting an investigation into a reported altercation at the Five Point Amphitheatre during Friday night’s Lady Antebellum concert involving the Fullerton police chief and one of his captains. He wrote:

“…upon their arrival they contacted two emergency medical technicians who alleged two men physically assaulted them while they were attempting to provide medical aid to an injured woman.”

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It turns out the injured woman was the Fullerton police chief’s wife. A source says she and her husband along with the Fullerton police captain and his wife had been drinking. The source says one of the officers put an EMT in a choke hold.

Both officers are being called suspects.

Residents who spoke to CBSLA’s Stacey Butler are glad the incident is being investigated.

“Not call somebody guilty until everything’s out there in the open so it is really important that they do an investigation first and then figure out what happened. Exactly what happened because obviously it’s perception-based reality,” said a Fullerton resident.

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The DA, Irvine Police and City of Fullerton are all investigating.