DALLAS (AP) — Police say autopsy results show a Houston-area woman was strangled and stabbed more than 20 times and that her 14-year-old son has confessed in the killing.

Police in La Marque (luh-MARK’) said Thursday that the 33-year-old woman was about five months pregnant when she was found dead in her home Saturday. The teen was found a day later in Houston.

Investigators say the teenager has been arrested on a murder charge. They said Thursday that he voluntarily confessed to the death.

Authorities have not indicated a motive.

Child welfare officials say the teen and a younger sibling had twice been removed from the woman’s custody because of her substance abuse and her partner’s domestic violence.

The Associated Press is not naming the mother because it would identify a juvenile.