A family friend of 11-year-old Audrii Cunningham was in jail Wednesday as prosecutors say they plan to charge him in the girl’s death after her body was found in a river near her rural Texas home.

Polk County Sheriff Byron Lyons said the body of the young girl — who went missing last week — was found Tuesday during a search in the Trinity River in a rural area north of Houston. Lyons said cell phone data was used to help identify places to look and that the local river authority slowed down the outflow of a reservoir to help search teams that were in the water.

Cunninham’s body was found about 10 miles (16 kilometers) from her home near Lake Livingston.

“My heart aches with this news,” Lyons said.

PAST COVERAGE Divers find body in Texas river of Audrii Cunningham, 11-year-old girl missing since last week

Audrii’s family had reported her missing on Thursday after she failed to return after school to her home in Livingston. After she was reported missing, investigators discovered that she never got on the bus to go to school that morning.

Polk County District Attorney Shelly Sitton said officials were preparing an arrest warrant for Don Steven McDougal, 42, on a recommended charge of capital murder. She said they do not yet know if they would seek the death penalty in the case.

Lyons said there is “substantial evidence” in the case, and that cell phone data and videos helped identify places to search. He added that the Trinity River Authority lowered water levels on the river, which led to the discovery of her body.

Authorities have said McDougal is a friend of the girl’s father and lived in a camper on the family’s property. Audrii lived with her father, grandparents and other family members, authorities said.

Lyons has said that in the past, McDougal had taken Audrii to the bus stop or would take her to school if she missed the bus.

A backpack that authorities believe belonged to the child was found Friday near the dam on Lake Livingston, one of the state’s largest lakes.

As authorities investigated Audrii’s disappearance last week, they had named McDougal as a person of interest and he was arrested Friday on an unrelated assault charge. He remains in jail on that charge. Jail records did not list an attorney for him.

Court records from Brazoria County, south of Houston, show McDougal pleaded no contest to two felony counts of enticing a child stemming from a 2007 incident and was sentenced to two years in prison.

The sheriff said that the girl’s body has been taken to the Harris County medical examiner’s office in Houston to determine the cause of death.

___

Associated Press writer Sean Murphy contributed to this report from Oklahoma City.