Houston ? A couple accused of beating their toddler to death, tucking her body in a plastic box and dumping it in Galveston Bay were indicted Wednesday on charges of capital murder.

Galveston County District Attorney Kurt Sistrunk said he had yet to decide whether to seek the death penalty against Kimberly Dawn Trenor and her husband, Royce Clyde Zeigler II, in the death of Trenor’s 2-year-old daughter, Riley Ann Sawyers.

The grand jury also charged Trenor and Zeigler with tampering with evidence, a second-degree felony punishable by two to 20 years in prison.

The couple was charged in November with tampering with evidence and injury to a child. DNA tests have since proven the body belonged to Riley, allowing the charges to be upgraded.

Trenor, 19, told authorities that she and her 24-year-old husband beat and tortured Riley to death in July in a discipline session that veered out of control. She said they hid the girl’s body in a shed for two months before dumping it in the bay.