Police in La Marque said in a statement that the 33-year-old woman was about five months pregnant when she was found dead in the home Saturday. An autopsy was performed Wednesday and shows most of her stab wounds were to the back and neck.
Investigators have not indicated a motive in the killing but said in the statement that, "The son did provide a voluntary statement in which he confessed to causing the death of his mother."
The teen initially was reported missing but was found a day later in Houston when a family member contacted police.
The boy was charged with a juvenile count of murder earlier this week and is being held at a juvenile detention facility.
The Associated Press is not naming the boy because he is a juvenile or his parents because it would identify the boy.
Investigators have determined that after the killing, the teen took a vehicle that had been loaned to his mother and drove about 200 miles west to Seguin, near San Antonio. He then traveled back to the Houston area before being taken into custody, police said. The reason for the trip to the San Antonio area was unclear.
Authorities have not said when the woman was attacked or how long she may have been dead before a neighbor discovered her body Saturday.
Child welfare officials said 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.
Estella Olguin, spokeswoman for Harris County Child Protective Services, has previously said the teen was first removed from the mother's custody in October 2005 and was in foster care until his paternal grandmother received custody of him in March 2007. He again was removed from his mother's custody in April 2010 and was in foster care until his father was awarded custody in February 2011.
According to court documents, the boy's mother and father had been fighting for custody of the boy for years. Both parents also had been jailed in recent years for failing to pay child support, and the woman had been involved in civil proceedings against four different men over child support and other matters.
The boy's paternal and maternal grandparents had been awarded custody of him at different times over the past eight years, when he was not sent back to live with his mother or father.
A Harris County court in 2006 found that the boy was at risk of abuse or neglect and the mother was ordered to undergo drug testing. When the boy was sent to live with his maternal grandmother in 2007, a judge wrote that there was credible evidence that both parents had a history or pattern of child neglect directed against the boy.
The boy began living with his paternal grandparents when his father was jailed in June 2014 and had very limited contact with his mother in the previous five years, according to an affidavit in August of that year by the boy's paternal grandfather. The grandfather said the boy's mother and father later went to his home in August 2014 and "both appeared to be intoxicated and under the influence" as they demanded that the boy be released to them.
The boy "was scared to go back with his parents, and threatened to run away," the grandfather's affidavit said.
"I am extremely concerned for (the boy's) safety and well-being if he were to reside or have unsupervised visitation with his mother or father," the grandfather said.
The grandfather also alleged the boy's father smoked marijuana in the boy's presence and that the boy was taking care of himself as his father was seldom home.
"I believe ... even allowing (the boy's parents) unsupervised visitation would significantly impair (the boy's) physical health or emotional well-being. I believe that it is in (the boy's) best interest to remain living in our home," the grandfather said then.
The boy's grandparents had filed a lawsuit in Houston asking for custody of the boy but dropped that suit in March without explanation.
The mother had faced various charges over the years and most recently was charged with driving with a suspended license in July. A warrant for her arrest was issued about two weeks before her death because she failed to appear in court on that charge.
Source: The Associated Press
"The system" destroys another one.