Photo: Joy Hummel with her daughter, Jody.
Officials say Hummel, 34, of Kennedale, Texas, is charged with fatally stabbing his pregnant wife, Joy, and using a baseball bat in the beating deaths of his 5-year-old daughter, Jodi, and his father-in-law, Clyde "Eddie" Bedford. Officials say he then set the home on fire.
Prosecutors plan to seek the death penalty for Hummel, according to the Fort Worth Star-Telegram.
Authorities say Hummel confessed to the killings. He was arrested Dec. 20 returning to Texas from Mexico.
Kennedale is about 10 miles southeast of Fort Worth.