Audrii Cunningham, the 11-year-old Texas girl who missed her school bus last week and was found dead in a river on Tuesday, died from blunt force trauma.

The Harris County Medical Examiner’s Office said the death was described as "homicidal violence" and her manner of death has been ruled a homicide following an autopsy, according to Fox 26 Houston.

Fox News Digital has reached out to the agency. 

An Amber Alert was issued for Cunningham after she failed to board the school bus on Feb. 15 and did not attend school.

TEXAS GIRL AUDRII CUNNINGHAM FOUND DEAD IN RIVER AS OFFICIALS EYE CAPITAL MURDER CHARGE FOR SUSPECT

She was found dead in a river on Tuesday and had a "large rock" tied to her body, authorities said. Officials have charged Don Steven McDougal, 42, with capital murder of a person between the ages of 10 and 15.

"The rope used was consistent with rope that was observed in [suspect Don] McDougal’s vehicle on a traffic stop two days prior," charging documents state.

McDougal, a family friend who lived in a trailer behind Cunningham's residence in Livingston, was initially taken into custody on Feb. 16 on an unrelated charge of aggravated assault.

He was tied to three locations of interest through cellphone data, investigators said. Cunningham was tied to two of those locations, including the Trinity River near the US Highway 59 bridge in Livingston, where she was found dead.

McDougal has a criminal history dating back to the early 2000s, when he was accused of dozens of crimes, and was convicted on two child enticement charges in 2008.

"He was probably taking her to… the bus stop, and we do feel that he was the last person to see Audrii," Polk County Sheriff Byron Lyons said of McDougal during a Monday press conference, adding that there were "some occasions" when McDougal would take Cunningham to the bus stop or even to school if she missed the bus.

Lyons said McDougal admitted to leaving with Cunningham on Thursday morning but didn't confirm if she boarded the bus to school. 

Fox News Digital's Audrey Conklin contributed to this report.