Parents: Unnamed father (deceased) & Rhonda O’Mara
Sibling: Kelly O’Mara
Dean was a farmer from the outback who came to Summer Bay with his younger sister Kelly for the Bachelor and Spinsters Ball fundraiser being held at the Walker farm. They met with April and Dexter, with Dean convincing Dexter to let them rent camping space in one of the farm fields. Dexter later thought better of it, since Sid was unaware of the arrangement, and when they ran into him and Kelly at the event he tried to put him off, but Dean simply gave him more money. The following morning, Dean seemed in a hurry to leave but Kelly refused to go with him first thing, wanting to stay around town for a while. Dean ended up tracking Kelly down and trying to drag her into his jeep but Xavier stepped in and Dean ended up leaving town without her.
A few weeks later, Dean returned to town to see Kelly, who had been staying with the Palmers. John and Gina were quickly taken with him although Xavier remained suspicious. Dean told Kelly he needed her to sign some land their father had left her over to him, since he needed to remortgage the whole area in order to keep the farm going. Kelly agreed but Xavier looked into it further and learned the bank was having the farm re-zoned. Dean admitted he actually intended to sell Kelly’s land. When Kelly refused to sign, Dean grabbed her and then fought with Xavier, during which John and Gina came home and threw him out.
John then saw a photo of the tattoo on Dean’s back and realised he was the one who had raped Bianca at the ball. Bianca realised the same thing when she saw Dean driving out of town but he ran her over, causing a minor shoulder injury, before she could say anything. When Liam found out the reason, he followed Dean on his bike and tricked him into pulling over, then overpowered him and called Georgina Watson to come and collect him. Kelly heard what had happened and that Bianca had been drugged with ketamine, which Dean had access to. She admitted a girl from where they lived had accused Dean of rape in similar circumstances but hadn’t been believed When Dean saw her at the police station and realised she thought he was guilty, he accused Xavier and Gina of turning her against him. It was later mentioned that after Kelly had made a statement against him Dean had confessed to the rape.