McKenzie Sessoms was found unresponsive in her home on Hairr Lane by a family member on the morning of Sept. 6, 2013.
Sessoms lived at the home with her father and siblings.
Sheriff Jimmy Thornton said an unnamed juvenile boy under the age of 16 is charged with murder and first-degree rape. He declined to identify the suspect or give additional details about how he knew Sessoms - citing the ongoing investigation.
Howard Jones, the suspect's grandfather, identified him as Antonio Trey Jones, who turned 15-years-old on Thursday.
"If he done it, I'm glad they got him. That's all I can say," said Jones.
The teen lived with his grandfather and his father next to the Sessoms' home.
Another family member said Trey had spoken in a vulgar way to McKenzie and had been banned from the girl's home.
At a Wednesday news conference, Thornton thanked the family for their patience during the eight months it took for detectives to collect enough evidence to make an arrest. Thornton said it was a particularly difficult case to solve.
"I cannot fathom the emotional strain they've had to endure while searching for answers," said Sheriff Thornton.
Sessoms' grandmother Cathy Starke thanked investigators on behalf of the entire family.
"Thank God they've done their job, and they've done it well," she said. "Now just keep us in your prayers."
Starke said her granddaughter was just like any other girl.
"She loved riding horses, riding four-wheelers, just hanging with her friends," said Starke. "She was an 11-year-old child."
Starke said the girl wanted to be a nurse or a teacher.
"She had her whole life planned," said Starke.
Starke also spoke about the suspect.
"I don't know what made him do it, but I hope that by him doing it, he realizes that he's really messed up his life as well as taking McKenzie away from us," said Starke.
Recently, Jones moved to Franklin County to be with his mother, and it's there where authorities arrested him, which sparked pain for now a second family in the horrible tragedy.
"He's just as sweet as he can be," said family friend Rhonda Wright. "Trey is being accused of terrible, terrible things that I just don't see him mentally capable of doing at all."
Wright is a close family friend, who described herself as like an aunt to Jones.
She said Wednesday that Jones is in special education. Though a teenager, but has the mind of a younger child, and has epilepsy.
Wright said when Jones came home from school Monday Sampson County detectives interrogated him for more than three hours without an adult.
"He told his mother yesterday they confused him," said Wright. "He was very confused. He said they turned some things around that he said."
Following that interview, Wright says Jones became upset -- repeating he didn't do it, and threatening to hurt himself.
The Sampson County sheriff said they have DNA evidence linking Jones to the crime. It's evidence his family plans to fight as he heads to arraignment.
Jones is currently being held in a detention center in New Hanover County.