Oscar, better known as Oz, was born and primarily raised in Atlantic City by his mother and his father, a small-time casino owner. After Oz's mother died when he was 15, his father decided to move the family to Las Vegas so he could own a major casino. Initially Oz learned the casino business from his father, but when his father died, two years prior to Oz's arrival in Los Angeles, Oz took over the day to day operations. Unfortunately, the mob in Las Vegas wanted to control Oz's casino like they controlled every other casino. Oz was first seen is Los Angeles calling his uncle, Massimo Marone, from a public phone, asking if he could come over because he needed help. Massimo hung up on him after telling him he was a legitimate businessman and wanted no part of Oz's world. Oz called back, begging him for help. Massimo still refused, and moments later, shots rang out. Oz was taken into the emergency room without identification, and only Massimo's phone number in his pocket.
The first person he really met in L.A. was med student Bridget Forrester. She was there when he woke, and he startled her when he grabbed her and asked where Paolo was. Bridget left the room to get a doctor and Oz tried to find Paolo on his own. Massimo arrived and informed Oz that Paolo was dead as a result of Oz having followed in his father's crooked footsteps. Massimo left just as a hitman arrived finish Oz off. The hitman took Bridget hostage. Oz was in no shape to help but Bridget managed to defend herself. Bridget and Oz began a tentative friendship. Oz was then moved to a new room, due to a bed shortage, which he shared with Amber (it is against hospital policy for men and women to share rooms but it is explained as necessary due to lack of room). Neither of them were thrilled to be sharing a room. The curtain was pulled between them but when he heard Amber talking about her son with a voice he recognized, he started to pay attention and announced himself to Deacon. Years earlier, Oz and his father had kicked Deacon out of Vegas for cheating in the casinos and stealing chips. Amber was overjoyed to hear it and wanted Oz to help her get custody of her son back, but Oz wanted nothing to do with her scheming. Bridget saved him from Amber, but shocked him when she admitted she was married to Deacon. Oscar admitted that at one time he and Deacon were good friends and Oz even got him a job at his father's casino, until Deacon started embezzling funds. He shared with Bridget his dream of owning his own club. He couldn't stop thinking about it after talking to her and decided to do it. He bought The Lair and renamed it Ozzz.
Oz made plans for the grand-opening of Ozzz, which included trying to get Macy Alexander Sharpe to perform. Deacon and Macy agreed after Oz promised he'd pay her upfront and let them know if there were any problems with his criminal past. As Oz was getting ready for the big night, he was confronted by two men from his past: hired killer Scarface, who tried to kill Oz in the hospital, and his boss, Jimmy Walton. The two wanted a piece of the action, but Oz told them to get out of his club. They left but told him he'd regret it. Keeping his promise to Deacon, he called to let them know he needed to talk to Deacon before Macy went on-stage. The club opened to a packed house. Oz was enjoying everything when he happened to glance up to see Scarface sabotaging the chandelier. Ox tried to save Macy before it fell on her but he was too late. She was rushed to the hospital and Deacon blamed Oz.
Oz blamed himself as well. Bridget tried to comfort him at the club, but he was inconsolable. Even though he turned the men in, he felt responsible for what happened to Macy. With Bridget's help, he went to the hospital to offer his apologies to a comatose Macy, barely escaping before Deacon could see him. He returned to the club, determined to close it forever and shut it down, when Amber showed up. Initially she sang for him, but that didn't do any good. She didn't convince Oz to hire her, but did remind him how much the club meant to him.
Oscar proposed to Bridget, and the two began planning a wedding. They left L.A. to head for Holland, so that Bridget could finish her studies, but Bridget returned alone a few months later, announcing that she and Oscar had broken up. Oscar presumably stayed in Holland.