Harris County Sheriff's deputies said Sunday they found the body of 67-year-old Hazel Billingsley inside a metal shed at the home on East Longwood Meadows.
Family members reportedly told investigators that 21-year Nathan Billingsley, the victim's grandson, had threatened to kill her.
Other relatives who lived with the victim grew worried after they too received threats, according to deputies.
ORIGINAL REPORT: Deputies discover grandmother dead at Cypress home
"He was texting messages to family members threatening to kill his mother and grandmother, to take the car," said Harris County Sgt. Beall.
When they could not reach Hazel by phone, family members drove to her home and allegedly found Nathan Billingsley loading his grandmother's things inside her car.
Investigators said this was right before he and his girlfriend took off, running away from what would become a very busy scene a short time later.
The family called 911, and when deputies arrived, they discovered the body of Hazel Billingsley wrapped in a blanket and placed inside a metal shed in the backyard.
"There was some blood found inside the trailer, on the back porch and after they did a search of the area they found the body of a white female," said Beall.
Meantime, deputies were hot on the trail for Nathan Billingsley and his girlfriend. They were both found in a nearby wooded area.
Investigators said Nathan was armed with a handgun, but he was taken into custody without incident.
The young couple was questioned, and Nathan Billingsley has been charged in the murder of his grandmother.
It is still not clear what allegedly set him off, or why he might have wanted to harm family members.
Relatives reportedly told investigators they feared he was unstable, and worried he would snap. They said he suffers from serious mental illness, and that they've been trying to get him help.
"He's been struggling for a long time with mental problems, and he's been on heavy drugs and in and out of the hospital," son-in-law Sonny Zamir said.
"Every time we try to commit him, he checks himself out so I actually blame the law for it, I really do."
Harris County Sheriff's deputies are continuing their investigation this morning.
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