Beneath the charm of Elliott Coulson lurked a man of violence, says ex-girlfriend Anne Thoroughgood Elliott Coulson and Anne Thoroughgood in 2009. A WOMAN who dated Mosman murder suspect Elliott Coulson for two "terrifying" years has revealed the accused killer hid a dark and dangerous side from friends and family. Homicide detectives interviewed Anne Thoroughgood for several hours over the weekend hoping to build a detailed profile on the 32-year-old Gold Coast man who is suspected of killing his former partner, Sydney finance employee Kate Malonyay. Ms Malonyay's battered body was found in her Mosman apartment last Monday, sparking a national manhunt. Coulson fled to the Gold Coast where he plunged to his death from the 26th floor of the luxury Marriott Hotel as detectives moved in to arrest him. Police believe Coulson may have returned to the Gold Coast specifically to silence Ms Thoroughgood once and for all. The 23-year-old personal trainer said Coulson seemed to be the perfect guy - handsome, oplite and kind. "He was really sweet, he seemed almost old-fashioned," she said. We were friends for quite a while before we actually went out together. However, once the couple started dating, Coulson began to change, she said. It was different. He became possessive and jealous. He would lie about things and say he was going away but then go out drinking. When Ms Thoroughgood dared to question Coulson, she said a darker, volatile and terrifying streak emerged - but always behind closed doors - while publicly maintaining the charm. "That was when his true colours showed," she said. He was aggressive, intimidating and threatened to hurt me, but never in front of anyone. Ms Thoroughgood began to have second throughts about the relationship and tried to create distance between them, but it only made him worse. "He would cling even tighter, become more possessive," she said. She said police believe her life may have been saved by keeping Coulson happy. "I tried to keep the peace," she said. I was 23, in my first serious relationship, I didn't know what to do, or where to turn. I knew that something wasn't right. Detectives said she did everything right, gradually removing herself from his life, one piece at a time. But the end came one terrifying night when she asked Coulson to return his key to her apartment. "He went crazy," she said. He attacked me, trying to take the keys back off me. Frightened and trapped, Ms Thoroughgood tried to text a friend for help, but Coulson stole her mobile. He pretended to be me and texted her that I was ok and just overreacting. She never came. Ms Thoroughgood was able to grab her mobile phone and called Coulson's parents. She left the line open and put the phone in her back pocket before Coulson launched into a brutal attack, choking her into unconsciousness and bashing and kicking her repeatedly. That phone call saved her life as Coulson's own parents helped her flee their son. They came. His parents are wonderful people," she said. Without them, I wouldn't be alive today. He was so shocked that they were there. That was the only thing that stopped him. All his life he had hidden that dark side from everyone - even his own parents. His mother was crying and told me she didn't know what had happened to him. My heart goes out to his parents, they didn't deserve any of this and they deserve to be left alone. He was a monster behind closed doors. I felt so trapped. No one knew what he was capable of. After she was safe, she tried to report the assault, but she said police turned her away. When she realised that going to court meant having to see Coulson and him knowing where she was, Ms Thoroughgood said she fled. I was afraid. I left my friends, my job, my home," she said. I moved several times, changed my number but he always found me. He stalked me for almost two years. Even when Coulson started dating Ms Malonyay, he continued stalking Ms Thoroughgood, sending abusive and threatening texts. The moment she realised Coulson had killed his girlfriend, she felt physically sick: "I felt so terrible for Kate. I really feel for her and what she went through and I can't help but think I wish I had done something to stop him. Police said he might have been here to shut me up for good. I can't think about it.