Wrathful abuser and perfectionist Laura Williams
Laura Williams (Fay Masterson) was the true main villainess of "Mommie Deadest," episode 8.22 of CSI: Miami (airdate May 10, 2010). She was the wife of salesman Chuck Williams, and the couple had three children together: Andrea, Cody, and Bradley. Furthermore, Laura was introduced as a "terrific" and "wonderful" housewife—but she was actually a cruel and sadistic child abuser who unleashed her wrath against their children whenever they weren't being "perfect" (in her mind).
Her backstory also revealed the Williams family used to live in Philadelphia and that her fury once reached deadly levels on August 23, 2003—a day when Chuck was out of town. Laura blamed Bradley for burning a hole in their house’s carpet (not knowing Andrea was responsible), so she forced her five-year-old son to drink from a container of lighter fluid, causing his death. Afterwards, Laura intimidated Chuck into keeping quiet by saying their two remaining children would be taken away from them if he told the truth. Bradley's death was also ruled to be accidental after she deceitfully claimed he got into the kitchen's cabinet when she wasn’t watching and swallowed the lighter fluid.
For over six years, including after they moved to Coral Gables, Laura's abusive and torturous ways continued. One example of it was when she angrily declared Andrea was "worthless" and started handcuffing her to her bed after she found out about her sneaking out to see her boyfriend Logan Price (a college baseball player) one night—with Logan later recounting how she despised him for even being in a relationship with her daughter. Additionally, preparations for the Williams family's 2009 Thanksgiving dinner suddenly went awry when the evil Laura lashed out at Andrea for getting food early "with [her] grubby little hands." Ignoring Chuck’s attempts to defend Andrea, she punished her for "[acting] like an animal" by forcing her to eat out of a dog bowl and coldly glared at Cody as he recorded the ordeal on the family's video camera. When Andrea called 911 after another instance of abuse on April 8, 2010, the crazed madwoman offered sodas to Officers Massano and Arvale—along with tricking them into believing the wrong address was given since "everything was fine."
The episode began with Laura and Chuck celebrating their 20th wedding anniversary by hosting a party at their house, but after the party ended, Cody feared he would receive more of her "discipline" (whether it was going to be Laura hitting him, claiming "something [was] wrong" with him, or worse) because he accidentally stained their couch with his red marker by leaving it open. Laura was then alerted to the sound of glass breaking and saw a lamp that Logan inadvertently broke while sneaking in to see his girlfriend. With his mother on the warpath once more, Cody hit her in her back with an aluminum baseball bat, causing her to fall onto the driveway. The wrathful villainess snarled at her only living son and prepared to abuse him again, only for Cody to fatally strike her on her head before hitting her seven more times.
It was followed by Andrea arriving at the scene—after which she tried to help Cody cover his tracks by instructing him to never tell anyone about what he had done, wiping down the bat, planting it among Logan's bats in his apartment, and falsely confessing to killing Laura. Even so, Cody was officially revealed as Laura's killer in the episode's climax when Natalia Boa Vista and Horatio Caine interviewed him with his father present. After Cody's tearful confession, Chuck attempted to take the fall, only for Horatio to ultimately say he would talk to the prosecutor in Cody's case. He added that Chuck and Andrea needed to tell "the whole story" about Laura's villainy.