CHARDON–A woman has pleaded guilty to reckless homicide for exercising her 73-year-old husband to death in a swimming pool, repeatedly refusing to let him leave the water.

Surveillance video showed Christine Newton-John, 41, pulling James Mason around the pool by his arms and legs, said Middlefield police Chief Joseph Stehlik

The chief said he counted 43 times in which Newton-John prevented her husband from leaving the water, and Mason rested his head on the side of the pool several times while gasping for breath.

"The video is bone-chilling," Stehlik said. "The whole case is very sinister.''

Mason had a heart attack on June 2 after the extended swim session. An officer who had investigated previous complaints that Mason was being abused pursued the case because he suspected there was more to the death, Stehlik said.

Newton-John pleaded guilty Thursday and faces up to five years in prison. No sentencing date was set.

Police did not immediately respond to a call Saturday seeking comment on a motive.

The video would have had a profound effect on a jury, Geauga County Prosecutor David Joyce said. But that wouldn't have been enough for a conviction if Newton-John had been charged with murder.

"You can see the man struggling for his life on the tape, but there is no audio, so we couldn't hear what he was saying," he said.

Geauga County Chief Public Defender Robert Umholtz, who represented Newton-John, declined to comment.

Mason was a longtime friend of his wife's family. He knew her as John Vallandingham before she had gender reassignment surgery in 1993 and changed her name in honor of the singer and star of the hit movie version of the musical "Grease.''

The couple were wed in 2006 in Kentucky, where people can change their gender on their birth certificate.