"Maternal Instinct"

Geographically, 2,500 miles separate the motels of Las Vegas's seamy underbelly from the Chateau Country of Delaware's Brandywine Valley. Culturally, they are even farther apart.

When Mesinar and Shields met Moseley, he was preparing for a black tie gala later that day to celebrate the opening of Fieldstone Golf Club. The club had been carved from Lisa Dean's vast land holdings and had been a recent gift to her husband.

Moseley, who declined the opportunity to have a lawyer present during the interview, tried to play cat and mouse with the two veteran investigators, but within a short time the self-styled super spook became hopelessly trapped in his own lies.

Soon, Moseley confessed to his part in the murder conspiracy, although he steadfastly refused to implicate his wife. Like a loyal centurion when beaten, Moseley fell on his own sword.

Mesinar and Shields suspected he was covering for her.

"Christopher Moseley did not have the authority or the money to do this without someone backing him," Mesinar said. "Everything he got, he got from his wife and her funds."

The investigators arrested Moseley and took him to the FBI office.

The next stop was Serendip, home of the du Pont heiress herself and monument to her family's fortune.

Mesinar and Shields were awed.

"We're small town guys, really, coming into a mansion that you're driving for two days just to get back to this house," Shields said.

"I've never seen a house that big," Mesinar said.

They found Lisa Dean in a smoke-filled room. She was a chain smoker, but other than that she appeared calm, unconcerned that her husband had just been arrested for murdering her son's lover. "She didn't give us the impression that she cared," Mesinar said. "I saw no emotion. All she did was sit and listen to us and deny knowing anything of the homicide."

The investigators, particularly Mesinar, had been around long enough to understand what was happening.

"Deep down in my heart, she knew what was going on, and she put her rubber stamp on everything," Mesinar said. Moseley had been her willing pawn. "I think he took the fall for Lisa. He did it to protect her."

The investigators left Serendip without a shred of evidence against Lisa Dean.