Leland Bates, 5, and River Bates, 3

The mother of the two Bradley County boys who died from hyperthermia last month was arrested and charged with two counts of felony murder Wednesday night.

Natasha Moses Bates

Natasha Mach'e Moses Bates, 26, was indicted by a grand jury after Bradley County Sheriff's Office detectives found reason to believe her sons died in a car, sheriff's spokesman Bob Gault said. An autopsy found the cause of death as hyperthermia, a condition that results from an extremely high core body temperature.

Bates is also charged with two counts of aggravated child abuse/endangerment, four counts of initiation of manufacture of methamphetamine and one count of promotion of methamphetamine manufacture.

Gault said the drug charges stemmed from a July 13 search of her home, when Bradley County sheriff's deputies teamed up with the Tennessee Methamphetamine Task Force for a two- to three-hour search.

The brothers, River Bates, 3, and Leland Bates, 5, died after their core temperatures soared to above 105 degrees on June 28. Moses told investigators she left her sons alone on a Slip 'n Slide for 45 minutes. She said she found the boys unresponsive and called 911 from her father's house, about a mile away.

River was transported to Skyridge Medical Center and was pronounced dead within 45 minutes of his mother's first 911 call. Leland Bates died the following day at Erlanger hospital.

Since that day, many questions surrounded the boys' deaths. Their father, Jonathan Bates, said on July 8 that Tasha had barely looked him in the eye since the incident. He said he asked her what happened that day, and all she said was, "I don't know."

Bates is being held at the Bradley County Jail without bond until her arraignment in Criminal Court on Aug. 13.