Prosecutors say Tylar Witt, who was 14 at the time, was furious that her mom Joanne Witt showed Tylar's diary to sheriff's deputies. Her mother had called authorities to claim Tylar's boyfriend, Steven Colver, then 19, committed statutory rape.
Tylar was accused of drugging her mother before she went to sleep in their upscale El Dorado Hills home before boyfriend Colver, authorities allege, stabbed Joanne Witt, who was 47, several times. Tylar and Steven dyed their hair and fled to the San Francisco area, where police arrested them days later, authorities say.
Blaming Each OtherLawyers for each defendant have maintained that the other defendant committed the murder. Outside a hearing Monday, Colver's attorney told reporters that the plea is further proof that Tylar stabbed her own mother.
"What young girl would plead guilty if she didn't do it?" attorney Dain Weiner asked. "The homicide had occurred before (Colver) had gotten to the house."
But Tylar's attorney tells PEOPLE his client took the deal "because she wanted to do the right thing" – not because she's conceding to stabbing her mother.
"There is no evidence she is the one that committed the stabbing, and I don't believe the DA or any detectives in the case believe she's the one that committed the stabbing," says Mark Ralphs, Tylar's public defender.
In court hearings on Friday and Monday, Tylar pleaded guilty to first-degree murder, and admitted to the special circumstances of lying in wait and of killing a witness to a crime – in this case her mother because of the rape report.
Under the deal, after Tylar testifies truthfully and Colver is either convicted or acquitted, Tylar's conviction will be reduced to second-degree murder without special circumstances, and the court will sentence her to no more than 15 years to life.