It was a day for lurid details Tuesday as authorities in El Dorado County began a multi-day hearing to determine if a 14-year-old El Dorado Hills girl should stand trial as an adult in the slaying of her mother, Joanne M. Witt, 47.

Tylar Marie Witt and her boyfriend, Steven Paul Colver, 19, are charged with killing Joanne Witt on June 11 or 12 after the mother filed a statutory rape report against Colver and kicked him out of her house.

Testimony by investigators Tuesday depicted a tumultuous mother-daughter relationship. The saga ended, authorities allege, with the mother's stabbing death at the hands of Colver, and the teen lovers fleeing toward San Francisco with plans to carry out a suicide pact.

Authorities say Joanne Witt agreed to take Colver into her home after her daughter told various people that he was a platonic "big brother" figure, and gay. But events spiraled into acrimony, then violence, investigators allege, after Joanne Witt discovered that Colver and her daughter were in a sexual relationship.

In a journal entry read in court Tuesday, Tylar Witt allegedly wrote: "My mother is driving me insane. I can't stand her company for more than five minutes. I hate her. She is bi-polarly (sic) insane and is turning me into the same thing. I just wish she would die somehow, some way … and leave me the (expletive) alone."

The journal, which the mother gave to police before her death, authorities say, goes on to describe in detail how Tylar Witt hoped her mother would be killed in a car crash. It also describes her sexual relationship with Colver and says: "I don't know how long we can keep our love from my mother."

Prosecutor Lisette Suder said Tuesday that on the day Joanne Witt died, Tylar spiked her mother's drink with drugs before calling Colver to come kill her. "She was the one who wanted this to happen," Suder said. "She was the mastermind behind it."

El Dorado Superior Court Judge James Wagoner ruled Tuesday afternoon that the "evidence before the court is sufficient to show her participation" in the crime. His ruling increases pressure on the defense to demonstrate, when the hearing continues Thursday, that Witt lacks the maturity to be held liable in adult court and should be tried in juvenile court.

Colver has pleaded not guilty to charges of murder with special circumstances. Witt has yet to enter a plea.

Joanne Witt's body was found in her home in the 200 block of Tattinger Court after co-workers at the El Dorado County Department of Transportation, where she worked in the engineering unit, reported her missing.

Authorities testified Tuesday that Tylar Witt's anger overflowed after she learned her mother had given her journal to a sheriff's investigator.

In filing the statutory rape allegation, Joanne Witt told authorities she had discovered her daughter hiding naked in a utility closet in Colver's room. She handed over the journal after the daughter refused to admit the sexual relationship to officers, investigators said.

Tylar Witt, dressed in a gray sweat shirt, dabbed her eyes with a sleeve as detectives read from her journal and outlined evidence in the case.

El Dorado County Sheriff's Detective Richard Fitzgerald testified that Witt told a friend that she spiked her mother's brandy beverage with Vicodin and "waited for her mom to pass out."

Another detective, Eric Harnage, testified that Valium and another prescription drug were found in the victim's body – but not Vicodin. He also said defensive wounds on Joanne Witt's hands indicated she was conscious during the attack.

Fitzgerald testified that Colver told a friend later, as they were smoking rock cocaine, that he had killed "Tylar's mom" with a butcher knife, stabbing her in the chest, neck and throat after scaling a back fence to bypass a neighborhood security gate.

Fitzgerald said the friend – a youth nicknamed "God" – told authorities that Colver then went to his car and retrieved a "shopping bag with a knife in it." He said the youth told authorities that the blade was "covered in blood."

Sheriff's Detective Michael Lensing, who interviewed Tylar Witt after she and Colver were detained by authorities in San Bruno on June 17, said the girl told him they "were going to run away together and commit suicide."

Fitzgerald said another friend told investigators that, before Joanne Witt was killed, Tylar asked him on his MySpace page if he knew how to get arsenic. He said he asked her if she intended to kill her mother and that Tylar answered she was "just kidding." After Joanne Witt was found dead, the friends had another online exchange.

"You sicken me beyond anything," the friend wrote, according to Fitzgerald. " … You really killed her."

"I didn't say that," the detective said Witt wrote back. "Now she's gone. I'm weeping. But I'm free."

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