Janette Alvarez, 50, worked as a certified nursing assistant for Terrace View Rehabilitation Center in Fullerton.
When Alvarez was arrested, police say she had several items belonging to her patients, including jewelry and credit cards.
Once of the victims is a former Major League Baseball player who played for the 1958 National League Champion Milwaukee Braves. His gold team ring and a matching broach given to the wives of the players are missing.
Authorities say the victims, unaware of the thefts at the time, referred Alvarez to other friends, who hired her for home care.
Police believe there may be more victims. If you have any information that may help investigators, you're urged to contact the Fullerton Police Department at (714) 738-6786.
Alvarez was arrested Nov. 8 and freed on $25,000 bail. She is scheduled to be arraigned Dec. 11.
She is charged with two counts of unauthorized use of personal identifying information and four counts of acquiring access cards using different names, all felonies, according to court records. The California Department of Public Health, who handles licensing for certified nursing assistants, is also investigating the matter.