A sex attacker who tied up and violently raped a woman in a Dublin hotel during a gaming convention has been jailed for 12 years.

Keith Hearne (28) brought a “rape kit” with a prop knife, handcuffs, mask and condoms and told the terrified victim: “I could break your neck here and now.”

Mr Justice Patrick McCarthy handed down the sentence at the Central Criminal Court today, saying the ordeal had been "devastating” for the victim.

Hearne stood with his arms by his side and stared at the judge as sentence was passed.

Judge McCarthy also ordered that Hearne in put under post-release probation supervision for five years.

He backdated the 12 year prison sentence to April, 2014.

Supporters of the victim burst into applause in the courtroom as Hearne was led away.

Hearne, from Tallaght, pleaded guilty to two counts of rape, one count of oral rape and one count of falsely imprisoning the woman at the Crowne Plaza hotel in Blanchardstown on July 4, 2015.

The victim, Dominique Meehan (24) from Donegal has waived her right to anonymity.

Read More: 'I could break your neck', Man carrying 'rape kit' told victim during hotel attack

Read More: 'I'm safe at last, now that my rapist is jailed' - young woman attacked in hotel meeting room

Previously, barrister Michael Bowman told the court that Hearne has mental health issues and suffers from a bipolar disorder.

He had not taken his medication for some period around the time of the attack.

At an earlier hearing, Garda Lisa Lawler told prosecuting counsel Shane Costelloe that Ms Meehan was volunteering at the ArcadeCon gaming convention in the hotel on the day in question.

She was preparing a presentation in a meeting room when Hearne entered the room and sat at the back. She became uneasy and moved to leave, but Hearne locked the door and threw her to the ground.

The attack stopped only when another conference worker entered the room using a hotel key card. Gardai were called and Hearne was arrested at the scene. He told gardai he had gone to the convention in the hopes of getting with another woman.

When that woman rejected him he said he had "anger flowing through him" and he then entered the meeting room and attacked his victim.

Ms Meehan described in evidence how she woke up every night crying for months after the attack, "thinking he had come back to finish the job".

"Before this, I wouldn't call myself an angry person, but now I punch walls, scream and walk out on conversations. I don't know what to do with this anger," she said.

The victim described how she has struggled with depression, post-traumatic stress disorder, self-harming and suicidal thoughts since she was raped.

"People see me smiling and laughing. They don't see me curled up under a blanket on my sofa," she said.

"He may go to prison, but I'm already there because of what he did."

Mr Bowman said his client engaged in "absolute opportunism and exploitation" of his victim and there was "no excuse" for what he did.

It was an "unspeakable intrusion and violation of her person", he added.

Hearne has no previous convictions and suffers from a range of conditions, including Aspergers Syndrome, ADHD, dyslexia and bi-polar disorder.