HUDSON COUNTY, N.J. -- A New Jersey doctor accused of arranging the slaying of his radio host wife to keep her from exposing a drug distribution ring he was running with an outlaw biker gang was found dead in his jail cell Friday in an apparent suicide.

Authorities did not release details of how Dr. James Kauffman died, but they said they suspected suicide and didn't see signs of foul play. He was found alone in his cell at the Hudson County jail, and guards checked on him when he did not respond, county spokesman James Kennelly told The Associated Press.

Kauffman was charged with arranging the 2012 killing of his wife, April, to prevent her from exposing an illegal drug distribution ring he was running with the Pagans biker gang.

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He had been the subject of death threats after his arrest, prompting his transfer from the Atlantic County Jail in Mays Landing, New Jersey, to the Hudson County jail, near New York City. Authorities said the switch was made for his own protection.

Prosecutors announced murder charges against James Kauffman, right, and a member of the Pagan Outlaw Motorcycle Gang in the May 2012 shooting death of April Kauffman, left. CBS Philly

A co-defendant in the case also is charged with trying to have Kauffman killed behind bars to prevent him from coming to trial.

Kauffman, 68, of Linwood, New Jersey, and co-defendant Ferdinand Augello, 61, of Petersburg, New Jersey, were arrested earlier this month and charged with murder in the death of Kauffman's 47-year-old wife, a local radio talk show host who advocated for veterans and who had won a community service award from the governor days before her death.

Her daughter Kimberly Pack had no immediate comment on news of her stepfather's death.

Atlantic County authorities said an investigation is continuing and declined further comment Friday.

Authorities say Kauffman arranged for his wife's murder to keep her from divorcing him in 2011 and exposing a lucrative drug ring he was running with the Pagans Outlaw Motorcycle Gang through his endocrinology practice.

Atlantic County Prosecutor Damon Tyner said Kauffman told Augello about his wife's threats and solicited him to have her killed. After about a year, a man who agreed to do it, Francis Mullholland, was driven to the home, where the doors had been left open, and was given a gun, authorities said. April Kauffman was shot twice.

Mullholland, who got about $20,000 in cash, was later found dead of a drug overdose, Tyner said.

Prosecutors also have charged Augello with planning to kill James Kauffman before he can go to trial.

Kauffman and Augello have maintained their innocence.