After 31 years on Texas’s death row, Lester Leroy Bower was executed tonight after the U.S. Supreme Court denied his final appeals without comment. His lethal injection began at 6:18 p.m. and he was pronounced dead at 6:36 p.m.

With his wife and two sisters in the death chamber viewing room in Huntsville, Texas, 67-year-old Bower, who has maintained his innocence, said, “I have fought the good fight, I held the faith. I am not going to say goodbye, I will simply say until we meet again. I love you very, very much.”

Bower spent more time on death row than any other prisoner executed in Texas to date. He was convicted and sentenced to die for an October 1983 quadruple murder inside an airplane hangar on a ranch outside Sherman, Texas, near the Oklahoma border. The state maintained that he singlehandedly executed four men — two of them former law enforcement officers — in an effort to steal a $4,500 ultralight aircraft.

But serious questions remained about the state’s investigation and prosecution of Bower. Indeed, in 1989, some five years after Bower was sentenced to death, the conviction began to unravel. Documents challenging the state’s case surfaced — thanks to the dogged work of Bower’s pro bono attorney team — and a woman came forward to say that she knew who killed the four men, and that it wasn’t Bower. She has maintained her story — corroborated by others — for nearly 26 years. (For more background and recent revelations, read The Intercept’s earlier story on the case.)

Although the evidence challenging the state’s case was compelling, it was not enough to convince the courts that Bower, at the least, deserved a new trial.

As such, with Bower’s execution, those lingering questions will likely go unanswered — and the possibility that the real culprits have escaped punishment remains real.

The potential for an innocent person to be executed is far from remote — and not just in Texas. Nationally, 153 people have been exonerated from death row. After Texas reinstated the death penalty following the U.S. Supreme Court ruling in Gregg v. Georgia, Texas resumed executions in December 1982. Bower, who would be sent to death row in 1984, went on to see 523 fellow prisoners sent to the death chamber. Tonight, Bower became the 526th person executed by Texas during the current “modern era” of the death penalty.