Trevor Lansing is the father of Ric Lansing, Sonny's half-brother.
Trevor has a long history with Sonny. Adela had an affair with Trevor when Sonny was young. Trevor was married at the time. Adela worked as his secretary. She would occasionally bring young Sonny into work with her. Trevor thought young Sonny was nothing but trouble and hated him.
Adela became pregnant with Trevor’s child. While she was pregnant, she stayed at Trevor’s house on Martha’s Vineyard. Adela accidently fell down the stairs while trying to get Sonny’s jacket on. Trevor was furious and told Adela that Sonny was nothing but trouble and that he couldn’t be around his new child. When Ric was born, Trevor told Adela to choose between Sonny and Ric. Adela chose to stay with Sonny.
Trevor, an attorney, arrived in Port Charles in 2007. It turned out that he had even more history with Sonny. Sonny’s girlfriend from Bensonhurst, Connie Falconeri, moved to Manhattan and became Kate Howard. She became involved with Trevor Lansing and he was her mentor.
Trevor hates Sonny with a passion and will do anything to destroy him. He works with the Zacchara crime family to continue to try and destroy Sonny. When their is a lethal toxin released and General Hospital has a fire, Trevor becomes unhinged and is eventually killed when he falls of the roof of he hospital.