LIVINGSTON, Texas — A convicted killer sentenced to death three times for the 1983 botched robbery and fatal shooting of a Houston bar owner has died on Texas death row of apparent natural causes.

Texas Department of Criminal Justice spokesman Robert Hurst says 71-year-old Raymond Deleon Martinez was found unresponsive Wednesday in his cell at the Polunsky Unit outside Livingston.

Martinez’s original death sentence was overturned in 1988 for a jury selection problem. A second death sentence was thrown out in 2007 for a jury instructions issue. He returned to death row in 2009 after a third punishment trial.

Evidence showed Martinez, identified as a prison gang leader, was among three people who in July 1983 entered the Long Branch Saloon in Houston where owner Herman Chavis was fatally shot. They fled empty-handed.