Villarreal was born in 1955 and lived as a drifter between Dallas and San Antonio.
He was arrested on March 11, 1981 after information reached police connecting him to a murder. In custody he described further killings, of men he had met and robbed, stabbed or struck with a hammer, between 1974 and 1981. Seven deaths are attributed to him on that basis.
This roster's status field reads that the sentence is unknown, and that is accurate: no accessible source records what he was convicted of, what he received, or what has happened to him since 1981.
So the entry consists of an arrest, a set of statements made in custody, and no verifiable disposition at all. It is retained because the roster carries it, and it should not be cited for seven murders.
It is among the least documented entries in this archive and belongs at the head of the re-check list; a Texas court record would settle it in a way no press summary can.