Paolo Caselli was first spotted in the bar at The Valley Inn talking to Leo du Pres. Leo asked his friend to help him by seducing Marian Chandler. It seemed an odd request, but Leo explained that he needed Marian to be caught in bed so that her marriage to Stuart would be ruined. Paolo agreed to help out for $30,000.
Paolo tried to play it cool and get Marian in bed the old fashioned away, but when Marian turned down his advances, Paolo laced her drink with a drug. Leo was furious when he learned that Paolo had drugged Marian.
Paolo bumped into Erica Kane at the hotel and immediately became interested in conquering her. Leo told Paolo that he wouldn't interfere in his plans if he agreed not to collect on the $30,000 he owed him. Paolo nodded his head, but never really said that he'd forget the money. Paolo tried to win over Erica with talk of exclusive real estate for sale. Erica was wise to the man's games and caught him in several lies. Erica threatened to turn Paolo over to the police, but she nixed those plans when she saw a use for Paolo --- using him to make David jealous.
Someone else had found a use for Paolo -- a totally different use. Vanessa Bennett Cortlandt turned to Paolo when things in her marriage to Palmer turned rocky. However, Paolo held this affair over Vanessa's head when he ran into financial problems with the man who supplied him cocaine. In an attempt to get Paolo out of life, Vanessa set up a scheme to frame Paolo for the theft of one of her expensive pieces of jewelry. In doing so, Vanessa slipped a strong sedative into Paolo's drink. That sedative proved lethal when it interacted with the drugs in Paolo's system. Leo took the fall for Paolo's death because he was the one who'd been found hovering over Paolo's body. The truth of Vanessa's involvement came out when David and Palmer made Vanessa think that she was having a heart attack. Police evidence against Leo disappeared and Vanessa's confession was never revealed to the police.