FORT BEND COUNTY, Texas - A Texas man has confessed to killing his parents in the prominent couple's Katy mansion, police tell CBS News' Crimesider.
Michael Walton, 54, and Lynda Walton, 52, were found shot to death in their $1.4 million home Thursday. Ryan Robert Walton, 20, one of the couple's four children, was arrested during a traffic stop Saturday about 20 miles south of Katy. He was driving a BMW automobile registered to his parents.
Ryan Walton confessed to the slayings within hours of his arrest, Fort Bend County Sheriff Troy Nehls told Crimesider.
"During the interview with investigators he was able to provide details of the crime scene of which he and/or the perpetrator would have only known," Nehls said.
Nehls couldn't provide specifics about the information Walton gave to police.
After securing a warrant, police searched the BMW Tuesday and discovered a .22 caliber rifle, Nehls said.
It's not yet clear whether it could be the murder weapon. Bullet casings from a small caliber weapon were discovered at the scene, and ballistics testing will determine whether or not the casings match the rifle, Nehls said.
Nehls also said that Ryan Walton had previous conflicts with family members. He also left home about three weeks prior to the shootings.
"There appeared to be some issues Ryan was having with his parents," Nehls said.
Derrick Walton, 24, found his parents dead Thursday evening, according to the station. The couple also has a 28-year-old son and 18-year-old daughter.
Officials quickly ruled out the possibility of a murder-suicide, reports CBS affiliate KHOU. Police were able to locate and speak with all of the couple's children except for Ryan.
The home -- nicknamed "The Governor's Mansion" because Michael Walton was the developer of the subdivision in which they lived- wasn't ransacked. The only thing missing was the BMW, Nehls said, which investigators saw on surveillance video leaving the gated subdivision around 9 a.m. Thursday.
"We needed to find Ryan," Nehls said. "We needed to find that vehicle."
Police announced that Ryan Walton was a person of interest in the case and that investigators were looking for him. Around 12:30 p.m. Saturday, Walton was arrested by an off-duty deputy sheriff during a traffic stop in Rosenberg, reports KHOU.
He didn't try to fight or flee during his arrest, Nehls said. As police questioned him, he appeared calm.
Walton is now being held without bond on two counts of murder. KHOU reports Ryan Walton was arrested for marijuana possession in 2011, but Nehls said police hadn't been called to the couple's home before the shootings.
A motive in the slayings isn't yet known, he said.
"I think that' something we're going to have to get from Ryan," Nehls said. "I don't know what would drive anyone to kill their parents."