The Chambers County Sheriff said 44-year-old Steven McDowell has confessed to strangling 37-year-old Crystal McDowell.
Their two children, ages 5 and 7, were there at the time, but may not have witnessed the killing.
"He is a little emotional, but he said very little," Sheriff Brian Hawthorne said. "He has been 100 percent cooperative. He was a person of interest as were others and every person involved, including Mr. McDowell, has been very cooperative."
The McDowells divorced in June, but investigators say Crystal was living with Steven and their two young children while her home was remodeled.
WATCH: New details in Baytown realtor's murder
Neighbors say the couple was close and loving, even after the divorce.
"He was a great father," said neighbor Doris Bell. "He had the kids all the time."
But just three weeks before her death, Crystal started dating well-known jeweler Paul Hargrave.
"I believe he knew exactly what he was doing. I think he knew the storm was coming in and this would help cover his tracks," Hargrave said. "I think I had a lot to do with his decision to do this and I can't help but feel responsible for that."
The department of family and protective services has placed the McDowells' children with their late mother's relatives.
Facebook posts on her professional realtor account show an upbeat mom, excited about her job.
On August 24th, the day before she went missing, McDowell posted, "Stay safe out there."
If you scroll through her page, you'll find dozens of posts thanking co-workers and congratulating home buyers.
On August 18th, she posted smiling pictures with home builders. She also thanks Hargrave.
TIMELINE: The Crystal McDowell murder case
- August 25: Crystal McDowell last seen at boyfriend's home
- August 26: Flooding from Hurricane Harvey hits Houston area
- August 29: McDowell's Mercedes found in flooded motel parking lot
- September 2: Active search for McDowell begins
- September 9: McDowell's body found in wooded area near Needlepoint Road
- September 9: Steven McDowell, victim's ex-husband, charged with murder
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