Updated

Two teenage boys in Utah are accused of luring a 14-year-old girl to a ditch where they robbed her and shot her in the head, leaving her critically wounded.

At a hearing in juvenile court Wednesday, a judge ordered the 16-year-olds to be held until another hearing next week. The defendants' names have not been made public because they are juveniles, but Cache County Attorney James Swink said he wants to try them as adults.

Police in Smithfield have not provided a motive for the attack on Deserae Turner, who is in a medically induced coma, but one of the boys said they were driven by greed.

They told police they lured Turner to the ditch last week by promising to sell her a knife. Instead, they shot her and then took her cellphone, iPod and $55, prosecutors said in charging documents.

Deserae was reported missing on the evening of Feb. 16, when she didn't return home from school. She was found early Friday in a dry canal about 90 miles north of Salt Lake City with a gunshot to the back of her head.

The documents say the boys originally planned to stab Deserae with knives of their own. After they arrived, one boy decided instead to use a gun he had brought, prosecutors said Tuesday.

They took money, tossed her backpack in a trash bin and destroyed her cellphone and iPod, prosecutors said.

The teen who brought the gun gave the spent shell casing to the other boy when he asked to keep it "as a memento," the charges state. Officers later found it displayed on his bedroom windowsill.

The teen who took the casing home told police that he saw his friend shoot a girl he didn't know, though investigators say text messages between the boys indicate they planned the robbery and shooting together.

The teen accused of pulling the trigger gave police a written note for Deserae's family that said, "I am so so so sorry," authorities said.

Smithfield, with a population of nearly 11,000, is one of several small bedroom communities around Logan, the largest city in the northern part of the heavily Mormon state. Deserae attended the area's only middle school.

The suspects do not have any serious criminal history, and both had no known problems at Smithfield's only high school, court and school officials say.

"What's hard for the community to process is why something like this would happen," said Tim Smith, spokesman for the Cache County School District, where all the teens went to school. "These types of events aren't typical for our valley."

Jill Parker, a county employee who is acting as a spokeswoman for Deserae's family, said they are doing the best they can. She declined to say why the family might believe their daughter was targeted.

Friends have set up a fundraising webpage that had brought in more than $30,000 as of Wednesday afternoon. The GoFundMe page says Turner is "fighting as hard as she can!" and adds that "every little bit will help their poor family with their ongoing family expenses as they go through this tough battle."

The Associated Press contributed to this report.