The citizen's arrest was made by a Target lost prevention officer at the retail store's Van Nuys location on Sepulveda Blvd when she was suspected of stealing shopping cart full toys and merchandise valued at $1,000. ET has learned that she had three carts full of items, but was only charged for a portion of what she loaded into her vehicle.
Richards was later booked at 7:29 p.m. PT on Sunday at the Valley Jail in Van Nuys, California, and was released Monday afternoon after posting $5,000 bail.
"I couldn't imagine Kim stealing or shoplifting anything. She is a giver," Richards' ex-husband Monty told ET. "I am in complete shock. Guaranteed this must be some kind of mistake, and the facts will come out soon. She was arrested for shoplifting toys in a cart, but this was a clear misunderstanding. This was not alcohol or drug related."
The 50-year-old reality star sat down exclusively with ET in July to address her struggles with sobriety and what really happened the night she was arrested for public intoxication at the Beverly Hills Hotel.
"I love sobriety," Richards told ET's Nischelle Turner. "I've always loved sobriety and relapsing was very hard for me. It was not easy. I have to say, don't take this wrong, but I really wanted to go treatment because I needed a break from what I was going through at home."
Richards had cited family stress as a contributing factor to her relapse, telling ET, "Monty, my ex-husband, is very sick and my son wasn't well. And I had to give away my dog, and I wasn't talking to my sister [Kyle Richards]."
During the interview, Richards told ET she had completed her treatment program and had been sober for more than a month, adding that she learned "a whole lot about myself" during that time.
"I dug deep into my past -- things that happened to me as a child, good and band, teenage years, relationships with all my loved ones, where they need to be mended, where they're very powerful," she said. "I worked on me."
Richards was arrested April 16 at the Beverly Hills Hotel following an incident, and entered rehab shortly thereafter. Richards said her "a-ha" moment that led her to seek treatment was that arrest, telling ET, "My arrest was my 'a-ha I get to go away now and rest and take a break from all this.' "