Crime Library: Criminal Minds and Methods

Mother Knows Best: The Story of Theresa Jimmie Cross


Theresa was charged in the torture slayings of her two daughters and arraigned in a Salt Lake City courtroom on November 15, 1993.  According to articles in the Sacramento Bee, she was extradited to Placer County the following month, arraigned before Superior Court Judge J. Richard Couzens and charged with two counts of murder, two counts of conspiracy to commit murder, and two special circumstances—multiple murder and murder by torture—charges, which could result in a death sentence.  Theresa pleaded not guilty and was remanded to the Sacramento County Jail.  That same day, Judge Couzens ordered William Robert Knorr prosecuted as an adult.  Robert eventually struck a deal with prosecutors and agreed to testify against Theresa in exchange for a lighter sentence.  One month later, all charges against him, except a single count of conspiracy regarding Sheila's death, were dropped.

When Theresa learned of the deal Robert made with the district attorney's office, she decided she did not want to take her chances with a death sentence and offered to plead guilty in exchange for her life.   District Attorney John O'Mara agreed and on October 17, 1995, Theresa changed her plea to guilty.   During sentencing, Judge William R. Ridgeway characterized Theresa's crimes as "callousness beyond belief," and sentenced her to two consecutive life sentences.  Theresa will be eligible for parole in 2027.  If she lives to see it, she will be 80 years old. 

Robert, who was still serving out his murder charge in Nevada, was eventually sentenced to three years in state prison.   The court ordered the sentence run concurrently with his 1991 murder sentence.  William was placed on probation for his role in the murders and ordered to undergo therapy.

On April 9, 2003, The Plain Dealer, a Cleveland, Ohio, newspaper, ran an article entitled: "Searching for answers on mothers who kill."  According to the story, an American mother kills her child at the rate of once every three days.  "These cases are patterned and predictable," said Michelle Oberman, a legal scholar and expert on women who kill their offspring.  "They are not shocking; they are mundane.  We just don't want to know what we know."