An Ohio man who bludgeoned his girlfriend to death and then stole her ATM card to buy crack cocaine apologized to the woman's family before he died by lethal injection Wednesday.

The sister of Michael Benge's victim said she doubted his remorse.

Benge's execution is Ohio's eighth lethal injection in 2010 — the most in a year since Ohio resumed capital punishment in 1999. The previous high since was seven in 2004.

Ohio's highest number of executions occurred in 1949, when 15 men died by electric chair.

Ohio's execution total this year is second to Texas, which has put 16 people to death in 2010. Texas executed a record 40 people in 2000 — the most since the state began using lethal injection in 1982.

Benge, 49, of Hamilton in southwest Ohio, was convicted of aggravated murder, aggravated robbery and gross abuse of a corpse in the 1993 death of Judith Gabbard, his live-in girlfriend, who was upset about his drug use.

Gabbard's daughter, son and brother watched Benge's execution.

"I can't apologize enough and I hope my death gives you closure," Benge said in his last statement, turning toward the family from his gurney. "That's all I can ask. Praise God and thanks."

Gabbard's daughter appeared nervous, kicking her foot and clutching a bottle of soda in her hand. The family was otherwise quiet during the procedure, which ended with Benge's death at 10:34 a.m.

"As for Judy's family, I've caused you all more pain than anyone should have to endure in a lifetime. I just hope someday you can find peace in your hearts," he said.

In February 1993, authorities say Benge killed Gabbard after arguing in her car along the Miami River.

Outside the vehicle, Benge beat Gabbard repeatedly in the head with a tire iron. He weighted her body with concrete and slid it into the river, leaving her car stuck in the bloodstained mud.

Benge swam across the river and found his way to a friend's house, where he confessed to the crime.

He told his friend's girlfriend that he intended to tell police he and his girlfriend were jumped by two black men and that his girlfriend was beaten.

He later gave Gabbard's ATM card to two black men and urged them to use it to extract drug money, a move prosecutors said was intended to frame them for the murder. The three withdrew a total of $400 from Gabbard's account for Benge's drug purchases.

In seeking mercy, his lawyers said Benge was physically abused by a stepfather and stepbrother and began abusing substances when he was 11 — first alcohol, then marijuana and eventually cocaine. They said he has a brain impairment as a result.

Gabbard's sister, Kathy Johnson, said after the execution that she didn't believe Benge was truly sorry.

"During the whole 17 years, he has blamed everyone but himself," she said. "He's blamed his family, he's blamed my sister, he's blamed my family. He has never taken responsibility for his own actions."

Wearing a pin with her sister's picture as she spoke, Johnson said at least now her sister, the oldest girl among nine siblings, could rest in peace.

Neither Benge's two children nor his mother witnessed his death. They and other family members spoke with him by phone on Tuesday and visited him Wednesday ahead of the 10 a.m. procedure. He chose to have his attorney, Randall Porter, as a witness. The two exchanged a nod before the lethal dose of thiopental sodium began to flow.

Benge continued to talk to officials in the room until he closed his eyes several minutes after his last statement.