A Texas mother accused of killing her two children by locking them in a hot car to "teach them a lesson" was indicted on Thursday.

Cynthia Marie Randolph, 25, was indicted on first-degree felony charges of causing serious bodily injury to a child. Randolph faces life in prison if convicted.

Randolph was arrested in June after her two toddlers -- Cavanaugh Ramirez, 1, and Juliet Ramirez, 2 -- were discovered unresponsive inside a locked car on May 26. Temperatures had reached close to 100 degrees by the time the children were found, FOX4 reported.

MOTHER, ACQUAINTANCE IN CUSTODY AFTER CHILD 'TORTURED'

The children were pronounced dead and an autopsy report released earlier this month ruled their deaths as homicides.

Randolph had initially told police she was in her home folding laundry and watching television when she realized her children were "gone." She said they were in the hot car for "no more than an hour." The mother then changed her story several times.

Police later said Randolph admitted she left the toddlers in the car to "teach them a lesson" because her daughter would get out of the car, according to the arrest warrant. She told investigators she thought her daughter would be able to get out with her brother when they were ready.

The Associated Press contributed to this report.