This is an archived article that was published on in 2014, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

The Utah teen who murdered his two younger brothers last year made his first court appearance Monday on new assault charges.

Aza Ray Vidinhar, 16, was charged last week in Ogden's 2nd District Court with third-degree felony assault by a prisoner, accused of assaulting another teen in a juvenile detention facility.

Vidinhar had his first court appearance Monday morning, where he was appointed a public defender. He will appear in court again next Tuesday, where he is expected to decide whether he wants a preliminary hearing in the new case.

According to a probable cause statement filed in court, Vidinhar was arrested Thursday after he allegedly assaulted another boy at the Mill Creek Detention facility, located at 790 W. 12th Street, Ogden.

Vidinhar allegedly "took a broom and attacked another male who is also in custody," according to the probable cause statement. Officers noted in the report that the other boy "did not fight back" and that Vidinhar allegedly initiated the fight. The alleged victim had minor bruises and scratches after the altercation.

Vidinhar pleaded guilty in June in juvenile court to one count of first-degree felony murder in connection with 10-year-old Alex Vidinhar's death, followed by a similar plea in adult court for killing his 4-year-old brother, Benjie Vidinhar.

The pleas were the result of an unusual plea agreement that allows the teen to be held in a juvenile facility until he is 21 years old, or until the juvenile system feels they can no longer help him.

At that time, defense attorney Todd Utzinger has said, the teen will be sentenced in adult court to a 15-years-to-life term at the Utah State Prison. The Utah Board of Pardons and Parole will then review the case, according to Utzinger.

According to court records, the latest charge was filed in the adult court because Vidinhar had already been certified as an adult in the court system on one of the murder charges. The teen is now being held in the Weber County jail without bail, according to court records, because he is currently being incarcerated for a felony offense and is accused of committing another felony.

Vidinhar was arrested the night of May 22, 2013, after his mother called 911 to report finding her 4-year-old son dead on the floor of her West Point home. She said Aza Vidinhar, then 15, and her 10-year-old son were both missing.

Sheriff's deputies subsequently found the 10-year-old's body in another part of the house. Both victims suffered "penetrating knife wounds," Davis County Sheriff Todd Richardson has said.

Officers later found Vidinhar walking in Layton, about 8 miles from his home.

A motive for the slayings has never publicly been revealed.

Twitter: @jm_miller