Updated

The leader of the fugitive gang known as the "Texas 7" was executed Wednesday for killing a suburban Dallas police officer during a robbery 11 years ago after organizing and pulling off Texas' biggest prison break.

George Rivas, 41, from El Paso, received lethal injection for gunning down Aubrey Hawkins, a 29-year-old Irving police officer who interrupted the gang's holdup of a sporting goods store on Christmas Eve in 2000. The seven escapees had fled a South Texas prison about two weeks earlier.

The gang was caught in Colorado about a month after the officer's death. One committed suicide rather than be arrested. Rivas and five others with lengthy sentences who bolted with him were returned to Texas where they separately were convicted of capital murder and sentenced to die.

Rivas became the second of the group executed.

The Texas Board of Pardons and Paroles this week voted 7-0, rejecting a clemency petition for Rivas. No 11th-hour appeals were made to try to head off the execution, the second this year in the nation's most active death penalty state.

"It's fair to say they're exhausted," attorney Mick Mickelson, who last met with Rivas a few weeks ago, said Tuesday. "He seemed ready for it."

Rivas and accomplices he handpicked for the escape broke out of the Texas Department of Criminal Justice Connally Unit, about an hour south of San Antonio, on Dec. 13, 2000. They overpowered workers, stole their clothes, broke into the prison armory for weapons and drove off in a prison truck.

They left behind an ominous note: "You haven't heard the last of us yet."

While out of prison, they supported themselves by committing robberies.

Hawkins was shot 11 times and run over with a stolen SUV driven by Rivas as the gang held up a sporting goods store closing on the holiday eve. They drove off with loot that included $70,000 in cash, 44 firearms and ammunition for the guns.

They were arrested a month later in Colorado, ending a six-week nationwide manhunt. One of the fugitives, Larry Harper, committed suicide as officers closed in.

In 2008, accomplice Michael Rodriguez, 45, who at the time of the breakout had a life term for arranging the slaying of his wife, ordered his appeals dropped and was executed. The four others remain on death row awaiting the outcome of court appeals.