An East Tennessee couple pleaded not guilty Friday to murder and child-abuse charges for allegedly forcing the man’s 5-year-old daughter to chug more than 2 liters of water and grape soda, causing her brain to swell and rupture, leading to her death.

Randall Lee Vaughn, 41, and Mary Vaughn, 58, of Surgoinsville, were arrested Wednesday after a two-year investigation into the death of the husband’s daughter, who was his wife’s stepdaughter.

The Hawkins County Sheriff’s Department said the two drove an unresponsive and discolored Alexa Linboom to the emergency room Jan. 1, 2012. She died two days later because of “acute fluid/water intoxication.” It caused her sodium level to drop, swelling the brain with water and severely damaging it. The death was eventually ruled a homicide.

The Vaughns disciplined Alexa by forcing her to drink about 2.4 liters of fluid, including several 12-ounce cans of grape soda, in a span of one to two hours, according to an autopsy report prepared by the Quillen College of Medicine at East Tennessee State University. She was bruised throughout her body and had cuts on her face, the report states.

The parents reportedly punished the girl because she took a sip of her stepmother’s grape soda without permission.

The Vaughns told investigators that Alexa had wet her pants and vomited several times before they brought her to the hospital about three hours later. They had tried to feed her oatmeal to calm her stomach, but she passed out while eating.

The report noted Alexa had moved to Tennessee about three months before her death because of allegations of neglect at her previous, unspecified home.

Both of the Vaughns were charged with first-degree murder, aggravated child abuse and two counts of aggravated child neglect.

An obituary in The Rogersville Review said Alexa Rae Linboom was a tomboy who liked coloring, animals, playing with her Barbie dolls
and being with her two brothers and three sisters.

Tennessee Department of Children’s Services spokesman Rob Johnson confirmed that Alexa had lived in the home with five other children, some of whom were siblings and some of whom were half-siblings. The five remaining children were taken into state custody in February 2013.

The Vaughns, who are being held on $500,000 bail, were given an Oct. 20 trial date.