Roberto Rojas entered the plea Monday to two counts of capital murder and another count of attempted capital murder as his trial was about to begin in Edinburg.
Rojas was arrested after his father-in-law beat him with a .22-caliber rifle authorities said Rojas used to beat his former wife. She survived, but killed were 8-year-old Mauro and 6-year-old Silvestre Garza, his stepsons; his 3-year-old son Osiel Rojas; and 45-year-old mother-in-law Amelia Rivera Flores.
Jurors Tuesday will be asked to accept his guilty plea and then begin hearing punishment testimony. Prosecutors are seeking death.