"The death of this innocent child, however, was absolutely not caused by any action attributed to my client," Davis said in a statement.
The couple was charged Wednesday with capital murder and tampering with evidence, and could face the death penalty or life in prison without parole if convicted.
Riley's identity was a mystery for weeks after a box holding her tiny body washed ashore in Galveston Bay. Her paternal grandmother in Ohio led police to Trenor, 19, and Zeigler, 24, after seeing a police artist's rendering of the murdered girl.
Trenor told Galveston County authorities that she and her husband of less than two months beat the girl with leather belts, held her head underwater in a bathtub and threw her across a room, her head slamming into a tile floor. She said they kept her body in a shed for one to two months before dumping it in the bay.
Shortly after the couple was arrested, Trenor's attorney told reporters that Zeigler had lost control while disciplining Riley for failing to say "please" and "yes sir."
Tommy Stickler Jr. said Zeigler had stayed home from work that day because he didn't believe Trenor was following his orders to spank Riley with a belt when she didn't say those things.
Davis initially declined to comment on Trenor's account beyond saying it wasn't credible. But on Thursday, he released a statement saying her "misstatements" led to Wednesday's indictment.
Zeigler "is positively not guilty of the offense for which he stands charged," Davis added.
The allegations against Zeigler mirror abuse his father's four ex-wives said they endured during their marriages decades ago.
Rita Grofer said the elder Royce Clyde Zeigler imposed similar disciplinary rules on their baby daughter in the 1970s and became violently enraged when she tried to intervene, once grabbing her by the throat and smashing her head into a kitchen cabinet.
In another ex-wife's divorce decree, she accused the elder Zeigler of tying an unidentified object around her left hand and tightening it until the bones snapped. A third ex-wife said he hit her, threw things at her, threatened to kill her and belittled her until she thought she was "dirt on the floor."
Davis said earlier this week he was shocked by the allegations and didn't believe his client experienced or witnessed abuse as a child.
