Divorce by DNA

Nanette Sexton is not the first woman in history to accuse her husband of being unfaithful. But she may become the first to go to court to try to prove it with DNA.

In a divorce case that seems like an episode of Dallas or Dynasty — but has real implications for others trying to prove infidelity — Sexton, a Harvard Ph.D. and great-niece of the famous sculptor Alexander Calder, is suing Richard Briggs Bailey, her multimillionaire third husband, for adultery.

Included in the cast is Bailey's former wife, Anita, who was at one time Sexton's close friend. The marriage and friendship fell apart when Bailey went off with Sexton, who became his fourth wife in 1993.

Triggering the 'Bad-Boy Clause'

Bailey gave Sexton a gift of $1 million when they married, and Sexton agreed that if they divorced, she would get no alimony. Then, five years into their marriage, they added a "bad boy clause," which guaranteed Sexton $20,000 a month for life if she was ever driven to divorce because she caught Bailey in infidelity. Six months later, Sexton says she walked into their bedroom at their farm in Vermont and saw a nightgown that wasn't hers.

"All of a sudden, my whole life just blew up in my face. I was just so shocked," she told ABCNEWS' Diane Sawyer in an exclusive interview. "At first I was just like frozen, like I couldn't move, had to sit and catch my breath and think, what does this mean?"

She said she confronted her husband, but he denied knowing anything about the nightgown. Faced with her husband's denial, Sexton says she sprang into action that night: She went back to their bedroom and pulled down the covers to discover there were hairs on the pillows and sheets.

"Someone's been sleeping in my bed," Sexton realized. She threw the nightgown, the sheets and the hair in a plastic bag.

Then she set out to find the identity of her rival. She pored over her husband's calendar and noticed that the letter A was marked on it periodically. She examined phone bills, and noticed a pattern of calls to and from a single number. She hired detectives who caught Bailey going to dinner and saw the same woman arriving at the farmhouse one night and not leaving until the next morning.

The detectives captured it all on videotape, and it turned out that the woman in the video was Bailey's ex-wife Anita. In a deposition, Bailey described the events that night as a "platonic sleepover."

Sexton didn't buy it. "It looked pretty romantic on those tapes," she said. "One has to ask, since her farmhouse is 0.7 miles down the road, why she needed to sleep overnight in our master bedroom with my husband."

What Sexton did next made headlines. She went to divorce court to attempt to prove infidelity with DNA. Proof of her husband's infidelity would trigger the "bad-boy clause" of their prenuptial agreement.

Was Bailey Mentally Impaired?

Sexton argued that when she married Bailey there was an understanding that she would spend much of her time in Florida, caring for her horses, while he was back in New England.

"That was what the whole agreement was about: to help me and augment what I had as income," she said.

But Bailey's five children said that their father never intended to support Sexton and her fancy riding horses, especially because their time apart left him feeling abandoned.

The children and Bailey's lawyers also said that when Bailey signed the revised prenuptial agreement containing the "bad-boy clause," he was suffering from the beginning stages of Alzheimer's. Sexton, they said, knew that Bailey was easy prey.

At the time of his deposition in the divorce case, Bailey does at times seem confused, giving his age as "33, going on 34," for example. And a neurologist who examined him a few months before the agreement was signed found that Bailey did have memory problems, especially with recent events.

Sexton denied that she exploited an ill man, and said that Bailey's children did not seem to think their father was too impaired when he sent them money.

"At the time that he was negotiating that contract with me, he was writing checks to them," she said. "They never thought: 'Oh gee, Dad just gave me $25,000. I wonder if he knows what he is doing.'"

In a videotaped deposition, William Kehoe, Bailey's lawyer, said that he had seen no signs of mental incapacity at the time the prenuptial agreement was amended.

"He was functioning, he was going to board meetings," said Sexton. "No one ever questioned Dick Bailey's competence until I filed for divorce."

DNA Ruled Admissible

Sexton still had her big weapon: the plastic bag she had kept in a safe deposit box, containing the nightgown, sheets and strands of hair. She sent them off to a lab in Denver, and word came back that the hair and a stain on the sheets contained the DNA of another woman, and DNA belonging to Bailey, though no indication of any sperm.

"I'll tell you what the DNA test did for me," said Sexton. "It gave me such a sense of relief that the lying was over and the truth … I had access to the truth."

Sexton believes it was Anita in her bed that night, but she denied any involvement and has refused to give a DNA sample to see if it matches.

Last October, Judge John Phillips of Palm Beach handed down a landmark ruling, saying the DNA evidence in Sexton's plastic bag could be admissible.

In the meantime, the judge wants to investigate Bailey's condition, which will delay the trial more than three years.

Bailey is currently in an Alzheimer's care facility and is represented by a legal guardian. Sexton said she has run up hundreds of thousands of dollars in legal fees, and said she has not spoken to her estranged husband in two years.

"I don't know what he has now, and they won't allow me to see him," she said. "If all this hadn't happened, I mean, I would be with Dick caring for him now."

The Bailey family declined an interview, but sent the following statement to Primetime Thursday: "Nanette Sexton's claims are baseless and not deserving of any response. Our father, Richard Bailey, was a quiet, dignified, extremely private man. He is thoroughly incapacitated by a cruel and debilitating disease."