<text>  A woman has told how she fulfilled a promise to her twin when she successfully fought to get her sex attacker jailed after she committed suicide. In a landmark legal case, Sharon Hennessy, 30, won justice for her sister Michelle who killed herself aged 27 in October 2012, a year after she was punched, kicked and sexually abused as she walked home from a night out. At the time of Michelles death, police were pursuing a rape case against her attacker Sean Thackaberry, but they said they would close it because there was no chance of a conviction without her evidence. Michelle left and her twin Sharon, pictured together on their 21st birthday. Michelle committed suicide a year about being attacked after a night out. Sharon reveals how she fought to bring her sisters attacker to justice . Sean Thackaberry was jailed for five years in a landmark case over attacking Michelle Hennessy . But Sharon, of Kildare Town, Ireland, had promised her beloved twin she would not let her attacker walk free. The pledge was important to Sharon because after initially being charged with rape, Thackaberry was released on bail and Michelle said she did not feel safe while he was on the streets. The family believe this was one of the reasons Michelle took her own life. Sharon reveals how Michelle - who was a fan of skydiving and nights out - changed after the attack. She said: She was afraid and vulnerable and instead of travelling to far-flung corners like she had done, she spent her time sat by the fire, knitting. I hardly ever saw her put on make-up and she never went out with friends, like she used to. Shed been so proud of her girly locks and her sense of fashion, but afterwards she didnt care. We were furious that Thackaberry hadnt been locked up and whenever Michelle left the house, his supporters would harass her. They sent her abusive messages online too, calling her a liar. The taunts and threats ground her down until she didnt feel human anymore. In October 2012 Michelle committed suicide at home. Her sister recalled finding out and desperately trying to reach her twins body. She said: I remember collapsing onto the stairs and screaming from the bottom of my belly. I screamed for all the pain and emotion that my twin sister was never able to scream. I screamed for the devastation she buried inside her, until it slowly destroyed every inch of her being. I screamed for the anger she felt at not being protected from the monster who stole her life. It was devastating. Michelle left and Sharon, pictured at three years old, had always been close and Sharon vowed to see her sisters attacker jailed, hiring a top lawyer and pestering police to keep the case open . Sharon, pictured at her 30th birthday left along with a tribute to her sister at the event right Michelle right and Sharon pictured together on their 27th birthday . Sharon was heartbroken when a lawyer told her family the ongoing case against Thackaberry would never see the light of day because of her sisters death. It felt like the final nail in Michelles coffin, she said. I felt like that monster was going to win again. So she hired a top lawyer and repeatedly pestered the police for the case to be pursued and the trial went ahead. In November 2013 Thackaberry, then 20, of Kildare Town, Ireland, appeared at Dublins Central Criminal Court where he admitted aggravated sexual assault. The court was told the former boxer had violently assaulted Michelle as he walked her home, dragging her onto wasteland around 250m from her home. Michelle pictured after skydiving in Spain. Her sister Sharon reveals how Michelle changed after the attack and wouldnt leave the house . Michelle - pictured left skydiving in Spain, and right on a night out afterwards - committed suicide a year after she was attacked by Sean Thackaberry after a night out . Remembering how Michelle felt after being attacked, her sister said: She told me, I thought I was going to die. Sharon told how Thackaberry winked at her as he was jailed for five years at Dublins Central Criminal Court. Her sister said: Id made my sister that promise. The lawyer said there hadnt been a case in Irish history like Michelles, where someone was convicted after the victim had died. But we wouldnt give up. Michelle was dead because of what that man did to her. We had hoped he would be prosecuted for rape, but it meant so much that Thackaberry had finally admitted what hed done. His sentence wasnt long enough for what hed done, but we were so relieved that we finally had justice for Michelle. She said she was now fighting for other victims. They werent even going to look at her case and didnt believe Michelle deserved justice, she said. Michelles case set a precedent for future court cases. Hopefully there wont be other victims like Michelle. But if there is, they wont just be forgotten, like Michelle threatened to be. People think its bad to talk about these things but, in fact, its one of the most important things in the world. Because its only by talking about them that more women who feel lost like Michelle will go and get help. In the year after her sisters death, Sharon has helped raise more than 30,000 21,000 for suicide awareness. 