A Massachusetts dad accused of viciously beating his 7-year-old son on Father's Day choked the boy, hit him with a belt and sat on him — all while his fiancee watched, according to newly released court documents.

Leslie Schuler, 36, also shoved Nathaniel Turner into a wall and struck him in the stomach in the June 21 attack that led to the boy's death a few days later, the documents say.

Schuler, of Worcester, is charged with murder and several accounts of battery. He is being held without bail.

The records allege that much of the abuse took place while Schuler's fiancee, Tiffany Hyman, looked on but made no attempt to stop it.

Nathaniel had moved from Alabama to live with his father, investigators say.

The documents were released Thursday at the request of The Telegram & Gazette newspaper, following a six-week impoundment requested by the prosecution.

Click for more from MyFOXBoston.com.

More coverage at The Telegram & Gazette.

The Associated Press contributed to this report.