Kissel wasin the ritzy town of Greenwich, where Sherman also happens to live.
Kissel was facing federal and state criminal charges in New York. The feds accused him of real estate fraud, and state prosecutors charged him with stealing nearly $4 million from his Manhattan apartment cooperative.
His lawyer, Philip Russell, said Kissel was planning to plead guilty Thursday in connection with the federal case in New York.
In divorce papers, Kissel's wife Hayley Kissel said her husband had sought treatment for a drinking problem and had committed fraud against her, including transferring property she owned in Vermont to his name and converting assets for his own use in violation of court orders. The couple has two children. She was moving out over the weekend.
Kissel also was being sued by a former business partner.
Kissel's death comes less than three years after his brother died in Hong Kong in a notorious crime known as "the milk shake murder." Robert Kissel's wife, Nancy, fed him a drug-laced milkshake and beat him to death with a statuette. She was convicted of murder and is serving a life sentence.
On The Early Show Wednesday, Sherman
Sherman observed that the timing of Kissel's death "would have been really appropriate if this was a suicide. He was facing a horrible divorce, custody fight, money problems, indictments in federal and state courts around the area. It would make sense if he killed himself. But this clearly was not a suicide.
"(There were) no signs of forced entry, so he obviously knew the person or had some reason to let them in. Feet bound and gagged, stabbed, it was reported he'd been shot. We don't know if that's confirmed. But, clearly an intentional execution. Not just a random act. Nothing stolen. This wasn't a burglary."
The list of suspects is very long, Sherman pointed out: "There is a host of people who had a great motive to kill him. I'm not talking about his wife. I think she's been cooperating and I think she's probably going to be cleared. … But he had bilked and apparently swindled so many people in so many different localities that any number of those folks could have either killed him or had him killed."
Sherman says the family's story is truly truth being stranger than fiction.
"If you tried to pitch this to Miramax, they wouldn't buy it," he remarked. "The brother is killed by his wife in Hong Kong, the wife gives the brother a milkshake laced with sedatives, she gives it to her child to give to her husband, and then she bludgeons him to death. And then there's a battle over their kids. And there's a sister on the West coast who winds up with those children, and then this happens here."