 After her sentencing Green continued to maintain that her recall of the night of the fire was limited . In the summer of 1996 , she wrote to her daughter claiming that she had taken more than the recommended doses of her medications that night . Similar letters to Michael Farrar varied from claims that she had no recollection of the night to firmly stating that she was innocent of the arson . She theorized that Margaret Hacker had set fire to the family 's house , and reiterated her claim from the show @-@ cause hearing that Tim had been the one to poison his father . Green wrote to author Ann Rule in 1996 asserting that , due to alcohol abuse , she had not had the mental capacity to start a fire . In a later interview with Rule , she blamed her cloudy thinking during the court hearings on her Prozac prescription , and stated that once she was off the drug , her mind became much clearer . 
