Juan Jose Uribe Pelaez, 32, is being held on a $500,000 bond after he allegedly stabbed both of his parents, killing his mother and injuring his father, League City police said.
After stabbing her mother to death the woman returned to the scene minutes later, pretending she didn't know what happened, prosecutors alleged.
Investigators say the suspect diluted fentanyl in his mother's iced tea on Saturday night.
The family of the woman killed made a deal with her killer, if he shows them where her remains are and they are found, he would be granted immediate release.
The sheriff says the neighbor saved a woman's life when her son shot at her point-blank. Investigators counted more than 20 bullet holes in a door.
A handyman confessed to the gruesome murder of a mom who was stabbed more than 55 times, a prosecutor said.