Court documents reveal more info about slain Buckeye teen, boyfriend

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By Jennifer Thomas By Jennifer Thomas
Robert Duffell By Jennifer Thomas Robert Duffell By Jennifer Thomas
Leah Costa By Christina O'Haver Leah Costa By Christina O'Haver
By Mike Gertzman By Mike Gertzman

TONOPAH, Ariz. – Newly released documents reveal more information about the death of a Buckeye teen whose body was found in the desert west of the Valley.

Leah Costa's body was found last week near Tonopah. The Maricopa County Sheriff's Office said the 15-year-old had been shot in the head.

Prosecutors are charging her 17-year-old boyfriend, Robert Duffell, in adult court.

The young couple ran away on Christmas Eve. It's believed the teens broke into a home in Tonopah on Dec. 26, stole three handguns and shot at the homeowner, according to court documents. Investigators believe Duffell shot and killed Leah later that day.

During the search for the teens, officers with the Arizona Department of Public Safety located Duffell wandering along Interstate 10 on Dec. 27. Officers described his appearance and behavior as disoriented.

When questioned, Duffell said he was with Leah, but the last place he saw her was at a gas station south of the I-10 and 339th Avenue. Court documents reveal he told the officers that he thought she was shot but did not provide additional information about where she was or who shot her. Duffell was turned over to family members.

After information about Leah was given to the news media, campers in the area described by Duffell contacted Buckeye police and reported that they saw a male and a female matching the teens' descriptions on Dec. 26.

They said the girl came to them asking for food. They then saw the male who was acting peculiar and was grabbing at his waistband, indicating he had a handgun, according to court documents. They told police that they later heard gunshots.

Sheriff's deputies searched the area of the campsite and found Leah's body in a rural desert area southwest of the Courthouse Road and Salome Highway intersection on Dec. 29.

Detectives questioned Duffell and said that he admitted to shooting Leah after an argument over the burglary.

Duffell was charged with first-degree murder, burglary and aggravated assault.

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