The former owner of a south Columbus medical center that provided illegal prescriptions died June 23 after being shot during an alleged home invasion the day before in Plain Township.

Columbus attorney Bradley Davis Barbin, who represents the family of Kevin B. Lake, said Lake was declared brain dead at OhioHealth Grant Medical Center.

Franklin County deputy sheriffs responded to the 7900 block of Schleppi Road at 7 a.m. June 22 and found Lake in the first-floor master bedroom with a gunshot wound.

Lake's 19-year-old son was upstairs when he called 911 and told the dispatcher that his father had heard someone breaking into the house. The son told the dispatcher that his father went downstairs, there were several gunshots and his father did not respond when he called down to him.

"The family was aware of death threats related to an ongoing federal tax-fraud investigation made prior to the attack on Kevin's life," Barbin said.

The attorney said no member of Lake's family was involved in the investigation.

At this time, investigators have no solid leads or suspect descriptions, said Maj. Steve Tucker of the Franklin County Sheriff's Office.

"Right now, it's just way too early to be able to determine exactly what the motive is. Really, all options are on the table. I mean everything is on the table right now," he said. "We are treating as a home invasion that, unfortunately, has resulted in the death of someone, and we will follow wherever the evidence leads."

Lake was a former trustee for Ohio University who pleaded guilty in February to drug, tax and fraud charges and to providing illegal prescriptions to hundred of patients, according to the U.S. Department of Justice. He was facing five years in prison.

He was found guilty of evading more than $3.5 million in taxes.

He agreed to pay restitution out of $29 million worth of earnings from his business Columbus Southern Medical Center and to forfeit the rest.

The state medical board permanently revoked Lake's osteopathic medicine license in February.

The Columbus Dispatch reporter Michael Huson contributed to this story.