DeLAND, Fla. – A 15-year-old boy accused of strangling his mother and burying her body at a Volusia County church is being charged as adult, officials said.

State Attorney R.J. Larizza announced the grand jury indictment during a news conference Thursday afternoon at the Volusia County Courthouse.

"I'm surprised, I'm shocked, I'm bewildered by the fact that we're in the position of having to prosecute a 15-year-old for murdering his mother," Larizza said.

The body of Gail Cleavenger was found buried under a fire pit at River City Church on Highbanks Road earlier this month after her son, Gregory Logan Ramos, confessed to killing her, sheriff's officials said.

Ramos was indicted Thursday on charges of first-degree murder, abuse of a corpse and tampering with a crime scene. Because he's being charged as an adult, he faces up to life in prison if convicted. Larizza said if he pleads to or is convicted of a lesser charge, it will be up to a judge to decide if he should be sentenced as a juvenile.

He will not the face the death penalty.

According to Volusia County Sheriff Mike Chitwood, Ramos confessed that it took 30 minutes to strangle his mother a couple days earlier at the family's home on Alicante Road in DeBary. Chitwood said Ramos was motivated by rage after the two got into a dispute about Ramos' school grades.

Deputies said Ramos used a wheelbarrow to load her body into a van and buried her body at the church.

Chitwood said the case was "one of the most disturbing and saddest I've seen in my career." He agreed with the decision to charge Ramos as an adult.

"I don't think we're talking about a typical 15-year-old kid. He made sure to tell us that he was highly intelligent over and over and over again and I hate to say this, but you want to act like a big boy, now you're going to get treated like a big boy," Chitwood said.

Ramos told detectives he enlisted the help of two friends to bury his mother's body and stage a burglary scene at the Alicante Road house. The friends, Dylan Ceglarek and Brian Porras, both of whom are 17, face charges of acting as accessories to a first-degree murder. They will also be charged as adults.

Deputies said Ramos reported that he returned home from school and discovered that the house had been burglarized, his mother was missing and her van was running in the driveway. He then made a 911 call to report the alleged burglary.

According to officials, Ramos later confessed to killing his mother. Chitwood said the teenager's confession was "cold and calculated" and lacked emotion.

"He is a soulless individual who thought he was going to outsmart everyone in the room," Chitwood said.