Kim Richards, former star of Bravo's hit reality TV series "The Real Housewives of Beverly Hills," will make an appearance on tonight's pre-taped episode of the network's late night talk show "Watch What Happens Live." In a sneak peek of the interview, Richards opens up about what led to her arrest at the Beverly Hill Hotel last April.

The 51-year-old was charged with resisting arrest, battery on a police officer and public intoxication after an incident April 16 at the hotel's Polo Lounge. Her public intoxication and battery charges were dropped, and she plead no contest to resisting arrest last September. A judge sentenced her to three years' probation, 30 days of community labor and 52 weeks of Alcoholics Anonymous meetings.

"I drank that night," Richards tells "Watch What Happens Live" host Andy Cohen. "It was no excuses, when you're working a program, which I wasn't doing at the time. I was before. I had three and a half years coming up on [sobriety], and I had a son that wasn't well, you know, had been sick. Monty [Brinson] was battling cancer, no excuse, but I stopped focusing on myself. I stopped taking the time for me and going to meetings because I was taking care of other people and stopped taking care of myself."

She explains that about two weeks prior to her arrest, she had a glass of wine at home with a girlfriend to ease the stress from all of the drama between her and her "Real Housewives of Beverly Hills" castmate Lisa Rinna. Two weeks later, on the night of her arrest, she visited her daughter Brooke Brinson's home and had another drink.

Feeling guilty after having her second drink in two weeks, Richards left Brinson's house while she was sleeping and got into her car, but she didn't want to drink and drive, so she stopped at the Beverly Hills Hotel, which is located only about two blocks from Brinson's home. The hotel was closed, but Richards insisted on sitting at her usual booth.

"I'm like, 'Please, I'm staying. I can't drive. I don't wanna drive. I'm scared,'" Richards recalls. "And [a worker] said, 'If you don't leave, we're calling the police,' and I really thought he was joking. And he called the police, and one thing led to another."

Watch the clip below and be sure to catch Richards' full interview on "Watch What Happens Live" airing tonight at 11 p.m. EST on Bravo.