MESA, Ariz. -- A 16-year-old boy who is accused of killing his mother and a 17-year-old alleged accomplice are being charged as adults in the case, according to the Mesa Police Department.
Michael Roy Helms and Christian Lee Blakely were arrested Saturday after the body of Tina Helms Spencer was found inside a backyard shed at her Mesa home.
The teens were booked into the juvenile detention center and will be moved to the Fourth Avenue Jail.
According to police, Helms told them that he killed his mom because he was upset that he was grounded.
Investigators said Helms also went after his stepfather. It was the stepfather who called 911 at about 4 a.m. Saturday. He told the dispatcher the teen had attacked him. He did not know at the time that his wife was dead already.
"This kid just kept assaulting and a several-minute struggle ensued," Mesa police Sgt. Tony Landato said.
According to Landato, the stepfather escaped and went to a nearby home to call the police.
By the time police arrived at the home in the neighborhood northeast of Gilbert and Baseline roads, the teen was gone, as was his mother's car. Seeing obvious signs of struggle, officers searched the property. They discovered Spencer's body in the shed.
The investigation took detectives to the home of the teen's friend.
"While we were there interviewing him [the friend], our 16-year-old suspect arrived at the residence and was quickly taken into custody by our detectives," Landato said.
Talking to the 16-year-old, police learned that he allegedly plotted to kill his mom and stepfather because he was mad that they had grounded him. He told detectives that he recruited Blakely to help.
Landato said the 16-year-old attacked Spencer as soon as she came home. According to court documents, Helms struck his mother with a frying pan, hit her with a hammer and choked her while Blakely watched the assault.
Detectives believe Helms then moved her body to the shed.
They also believe the teens tried to clean up the scene and dispose of evidence.
The friend had already left when the stepfather arrived home and was attacked. According to the court papers, the 16-year-old hit him over the head with a frying pan, punched him and choked him. He suffered severe swelling on his face and eye.
According to the court documents, police noted that Blakely was not threatened and had several opportunities to leave the residence. He made no attempts to notify police of the murder and then admitted to checking the news while at work the next day.
Helms is facing charges of first-degree murder, attempted first-degree murder, aggravated assault, tampering with evidence and concealment of a dead body. Blakely is facing charges of first-degree murder as an accomplice, concealment of a dead body and tampering with evidence. They are each being held on a $1 million bond.