KINGMAN - Veronica Bravo, 17, of Kingman, accepted a plea agreement on Aug. 21 and pleaded guilty to attempted first-degree murder, a class 2 felony.
She earlier was charged with first-degree murder.
Bravo said she, Ray Carlton and the victim, Christina Buus, were in a vehicle heading southbound toward Kingman on U.S. Highway 93 at the time of the murder last summer.
Bravo admitted that she stabbed Buus, 19, several times before Carlton, 23, also of Kingman, allegedly shot Buus in the head.
She also admitted to using methamphetamine at the time of the murder.
Although a class 2 felony is only punishable with a presumptive term of imprisonment of 10-1/2 years, the court can increase that to 21 years or decrease it to seven years.
The plea agreement made it clear Bravo would receive a sentence of 21 years in prison without the possibility of probation.
If Bravo had chosen to go to trial, the punishment for conviction of first-degree murder could either be life in prison or life in prison with guaranteed 25 years jail time.
Neither punishment would be favorable compared with the offer of 21 years in prison, according to Deputy County Attorney Lee Jantzen, the prosecutor.
Mohave County Superior Court Judge Steven Conn reminded Bravo several times during a jury trial management hearing that she has the right to ask for two separate trials for the first-degree murder and methamphetamine-use charges.
If the state fails to prove Bravo used methamphetamine while committing the crime, she might have the opportunity for probation after serving a certain number of years of her jail time, Conn said.
Jantzen heard Conn's comments about Bravo's methamphetamine use and said he did not think it would be a big burden for the state to prove.
He said Bravo had told investigators clearly that she used methamphetamine at the time of the crime and that record could be easily used against her in court.
Bravo told the judge she had talked to her attorney about the details of the plea agreement and decided to accept it.
As a condition of the plea agreement offer, Bravo agreed to waive her right to remain silent and will testify against Carlton, her co-defendant.
Jantzen said the state offered Bravo the agreement partly to give her the opportunity to tell the whole story to the jury during Carlton's trial.
"The reason we offer her the deal is to get her significant punishment, not to downplay her involvement in the case, while having her available to testify," he said.
Jantzen talked to the victim's family members briefly after the hearing.
He said the family was unhappy with the plea agreement conditions, but understood the plea would help the state prosecute Carlton.
Bravo's final sentencing is scheduled for Sept. 29, three days after Carlton starts his jury trial.
Carlton has been charged with first-degree murder and will either face a life in prison or life in prison with guaranteed 25 years jail time.
Jantzen said the state does not plan to seek the death penalty against Carlton.