By Karen Brooks
AUSTIN, Texas (Reuters) - A man convicted of killing his girlfriend's sister and a university associate dean is scheduled to be executed on Thursday in Texas, marking a second execution in the state this week.
Vaughn Ross, 41, is set to die by lethal injection after 6 p.m. local time (CST) at a state prison in Huntsville, Texas.
The victims, Douglas Birdsall and Viola McVade, were found shot to death in January 2001 in Birdsall's car in a ravine in Lubbock, Texas, according to an account of the case from the state attorney general's office.
Birdsall, 53, and McVade, 18, had been shot several times and had died from gunshots to the head, the account said.
McVade was the sister of Ross's girlfriend, and Birdsall was an associate dean of libraries at Texas Tech University in Lubbock.
Ross, who held a college degree from a Missouri university and was putting himself through architecture classes at Texas Tech, was convicted and sentenced to death in September 2002.
He pleaded not guilty to the charges, with his lawyers arguing he could not have committed the crime alone and that police had planted evidence.
Ross told prosecutors that he had been fighting with McVade and had threatened her the night before her body was found, according to the attorney general's account.
McVade had repeatedly called her sister that night, and Ross also got on the phone. McVade put ex-boyfriends of her sister on the phone, one of whom called Ross a "coward," according to court filings. The girlfriend said Ross told McVade on the phone that if she showed up at his house, "I will shoot you," according to court filings.
After Ross gave police permission to search his house, investigators found a bloodstained sweatshirt with DNA from both Ross and Birdsall.
Inside Birdsall's car, a latex glove carried DNA that matched both men, and a large pool of blood in the alley behind Ross' apartment matched Birdsall's DNA. The car and bodies were found about four miles from Ross' home.
After his arrest, while he was in jail, Ross told his mother he "might have" committed the crime, the account said.
If Ross's conviction is carried out, he will be the 10th inmate executed in Texas and the 20th in the United States this year, according to the Death Penalty Information Center.
On Tuesday, Texas executed John Manuel Quintanilla Jr. for the murder of a man during a robbery at a game room.
(Reporting by Karen Brooks; Editing by Greg McCune and Ken Wills)