The OCSD confirms that special officer Monica Alston is on administrative leave pending the result of the investigation.
The FBI has also confirmed that agents searched Alston's Irvine home.
The Orange County Register reports that Alston posted social media photos of herself outside the Capitol and a video from inside the building.
The position of special officer is not a full sheriff's deputy but is used for assignments such as security at airports, courthouses and jails.
Federal authorities have investigated hundreds of people across the country for allegedly taking part in the violent protests at the Capitol that day and made well over 100 arrests.
Those who have been charged are listed in this document from the Justice Department.
Three Beverly Hills residents facing charges related to violence at the Capitol
Victorville gym owner accused of participating in Capitol riot