During a court appearance Tuesday, Tanya Lori Ahasteen pleaded guilty to second-degree murder of Alvin “AJ” Cayatineto on March 9 at his home south of Cortez.

The preliminary plea agreement stipulates a 24-year sentence to the Department of Corrections plus five years of parole, said Deputy District Attorney Mark Franklin. Ahasteen originally was charged with first-degree murder, according to a Montezuma County Sheriff’s Office arrest warrant.

The plea deal was negotiated by former District Attorney Matt Margeson, Franklin said. Margeson was recently appointed by Gov. Jared Polis to serve as Dolores County Judge.

Chief Judge Todd Plewe provisionally accepted Ahasteen’s plea agreement, pending a presentence investigation report.

Sentencing is scheduled for 9 a.m. May 15. Representatives of the victim and defendant will be allowed to testify before the sentence is decided.

The stipulated 24-year sentence proposed is the higher end of the sentencing range for second-degree murder, a Class 2 felony, Plewe said.

When Plewe asked about the factual basis for the murder charge, Franklin responded that Ahasteen was arrested as a suspect in the homicide of Cayatineto “and tried to place blame on her sister,” who is identified as Latonya Laura Ahasteen.

During a subsequent interview, Tanya Ahasteen said she caused the death of the victim, Franklin said.

During the court hearing, Ahasteen’s attorney, Barrie Newberger King, referred to evidentiary issues in the case, lack of witnesses and statements that are potentially inadmissible.

Ahasteen remains in custody at the Montezuma County Detention Center on a $1 million bond.

Her sister, Latonya Laura Ahasteen, was charged with second-degree murder in the death of Cayatineto, according to the Montezuma County Sheriff’s Office. Her case is pending in court, and she is in custody at the county jail on a $750,000 bond.

Cayatineto’s body was discovered the evening of March 11 by family members who visited his camp trailer, parked at 5603 U.S. Highway 491, the property of CDL Trucking, where he worked.

He had been beaten on the head and stabbed in the chest and neck, according to the autopsy and arrest affidavit.

According to the arrest affidavit, Latonya Ahasteen and her sister, Tanya Ahasteen, were living at the trailer with Cayatineto, who was their uncle.

During an interview with Montezuma County Sheriff’s Detective John Haynes, Tanya Ahasteen said she and Latonya Ahasteen had started drinking the morning of March 9 while Cayatineto was away receiving dialysis treatment.

After he returned, he and Latonya Ahasteen began arguing, according to the affidavit.

During initial interviews with police, Tanya Ahasteen said she tried to get them to stop arguing then left the camp trailer and sat in Cayatineto’s Nissan Rogue and listened to music.

When she went back in the trailer, she told investigators, Latonya Ahasteen had a pole in one hand and knife in another, and Cayatineto was gasping for air and covered in blood. In a later interview with police, Tanya Ahasteen said she caused the death of Cayatineto, according to Deputy DA Franklin.

On March 9, the sisters left the scene in the Nissan Rogue, with Tanya Ahasteen driving. A short time later, she got in a vehicle crash on North Broadway and was arrested for DUI by the Cortez Police Department. The sisters were not identified as suspects in the death of Cayatineto until later.

Latonya Ahasteen was arrested on a homicide warrant on March 16 at The Bridge Shelter in Cortez.

Tanya Ahasteen was arrested on a warrant in July in Mesa, Arizona, and extradited to Montezuma County.

The investigation involved the Sheriff’s Office, Colorado Bureau of Investigation and Navajo Police. Evidence emerged that alleged Tanya Ahasteen also was involved in the homicide of Cayatineto, according to a June 29 arrest warrant affidavit written by Montezuma County Sheriff Detective Travis Anderson.

The affidavit says a witness told investigators he had received messages via Facebook and text from one or both of the sisters indicating they may have both planned the homicide, that it might have been carried out and that they fled the scene. Police obtained warrants to analyze the Facebook and phone messages.

According to the arrest affidavit, based on the investigation, Tanya Ahasteen is suspected of first-degree murder because “she had specific knowledge of the manner in which AJ Cayatineto was murdered,” and allegedly told a witness about plans to kill him. The weapons allegedly used in the attack on Cayatineto were recovered “after the fact in Tanya and Latonya’s possession.”