The father of a Texas toddler found dead in October was charged with murder Friday. Wesley Mathews, 37, was indicted on a capital murder charge by a grand jury, according to CBS News. He remained behind bars at the Dallas County Jail on bond of $1 million.

“We will be tenacious, we will be persistent, and we will prosecute this case to the fullest,” Dallas County District Attorney Faith Johnson said at a press conference Friday.

In addition to those charges, Wesley was already charged with felony injury to a child. He was also indicted Friday for tampering with evidence, KXAS-TV reported. The girl’s mother, Sini Mathews, was previously arrested in the case for child abandonment or child endangerment.

Three year old Sherin, who had developmental disabilities, was reported missing by her adoptive parents, Wesley and Sini Mathews, in October. Wesley initially told authorities he left her outside in the middle of the night as punishment for not drinking her milk and that when he returned, she was gone.

Sherin’s body was found a few weeks later in a culvert. Wesley then told authorities he “physically assisted” the girl when she refused to drink her milk. She then choked on the milk and died, he told police. He later admitted to removing her body from the home.

The results of an autopsy released earlier this month showed Sherin died of “homicidal violence,” though the specifics were not released, according to WFAA-TV. Evidence revealed in the autopsy, however, was what led police to seek a capital murder charge. Authorities said they had not yet decided whether the death penalty would be sought.

After Sherin’s body was found, reports emerged that a pediatrician warned Child Protective Services that Sherin may have been getting abused. Suzanne Dakil testified that she told CPS she saw Sherin for broken bones and other injuries. CPS vowed to find out how and why Sherin’s case had slipped through the cracks and called it “unacceptable.”

Wesley Mathews (left), the adoptive father of Sherin Mathews, said in his confession the 3-year-old choked to death on milk.