After hearing opening statements in her trial Wednesday and the testimony of only one witness, Walker, 44, offered the plea against her lawyer's advice, accepting the maximum sentence of life in prison, the South Florida Sun Sentinel reported Thursday.
Walker was accused of killing and nearly decapitating Carmen Santiago, 76, in 2007, allegedly motivated by her mother's refusal to move to North Carolina from her Hollywood, Fla., home, the newspaper said.
Prosecuting attorney Shari Tate said Walker was prepared with "a web of cover-up and deceit" that included the stockpiling of cleaning supplies, crime-scene books, protective goggles and a body suit.
Of Walker's sudden plea in court, Arthur Marchetta Jr., her attorney, said she is "desperate to try and right some wrongs and in her mind this is the way she can do it."
Notable deaths of 2014 [PHOTOS]