Steven Thomas, 53, was picked up Monday in Austin and charged with murder in the fatal attack on 73-year-old Mildred McKinney in her home on the southwest side of the county.
Notorious serial killer Henry Lee Lucas had earlier confessed to the slaying; however, DNA testing showed he was not the culprit, the Williamson County Sheriff's Office said in a written statement.
It was also DNA that led deputies to Thomas along with a fingerprint found at the scene. Sheriff's detectives said they had previously questioned Thomas about the crime but he denied knowing McKinney or having anything to do with her death.
The sheriff's office and county prosecutors did not immediately provide further details.