Martin Hay, 24, has a growing number of convictions and his latest violent outburst left Ryan Mr Mullen’s body peppered with puncture wounds and soaked in blood.

A picture posted on his Facebook page also shows him posing with a giant machete, while another snap shows off a tattoo on his arm which reads ‘no comment’.

The violence erupted on March 12 this year when tattoo artist William Reston was at Hay’s sister’s Onslow Road home to ink a new design on the woman’s leg.

Mr Mullen turned up in a drunken state and continued to knock back the booze before matters took a turn for the worse.

A row involving Hay’s sister, Karen Donaghy, and Mr Mullen escalated and Mr Mullen was asked to leave before being bundled out the door at which point Hay appeared on the scene.

By the time he finished knifing Mr Mullen, there was blood all over this hands and arms.

Police followed a trail of blood all the way to Donaghy’s door where they found Hay with his top off and blood smeared on his arm.

There was also a blood-stained T-shirt discovered which, following a forensic examination, was found to have Hay’s DNA on it.

Last week the 24-year-old, who has an alarming history of violence, stood trial at Dumbarton Sheriff Court where he consistently denied the charge, claiming Mr Reston and another unknown man had carried out the assault.

Mr Mullen also told the court Hay was an innocent man but on the last day of the trial fiscal depute Sarah Healing urged the jury to dismiss Mr Mullen’s evidence which she said was “not reliable or credible”.

Describing Hay as a “dangerous individual” who had carried out the attack in a “callous, vicious and cold” manner, she said: “When you look at the evidence as a whole it provides compelling proof that Martin Hay is guilty of the charge on the indictment.” Recalling evidence given by the tattoo artist Mr Reston, Ms Healing reminded the jury of the chain of events he witnessed unfolding on a day when the only blood he was expecting to see was from his tattoo needle. It all started when Mr Mullen and his former lover began arguing and Mr Mullen was escorted outside.

Ms Healing added: “That’s when Martin Hay appeared on the scene. He had armed himself with a knife and at that time he decided to involve himself in the argument between his sister and her ex-partner.

“Rather than call the police, Martin Hay took the law into his own hands.” According to Mr Reston, Hay started lashing out indiscriminately. The witness also described hearing the sound of the victim’s skin being penetrated by the blows.

Ms Healing continued: “He could see Martin Hay running round him, stabbing and slashing Ryan Mr Mullen. He could hear the knife cutting through the skin. He was disgusted. He wished he had never gone to the house.” Mr Mullen was left with wounds to his back and buttocks and has been permanently scarred by the attack but when he took the witness box earlier in the trial he claimed Hay was not to blame instead telling the jurors the attack was carried out by the “tattoo guy” and another unknown male with “a white track suit and bleached blonde hair”.

Hay’s defence agent Ian Sievwright told the jury his client’s defence was straight forward, namely that the wrong person was in the dock and one of the people responsible for the attack was William Reston.

He said: “Ryan Mr Mullen accepts that he was very drunk that day but if there was one thing that he was sure of it was that Martin Hay was not responsible for the attack on him. If the man in the dock was responsible he would have no difficulty in pointing him out without any hesitation. He did not.” Mr Sievwright cast doubt on the evidence given by Mr Reston, who was originally charged with the crime before the case against him was dropped by prosecutors, and urged the jurors “not to be fooled” by his evidence.

He continued: “Ryan Mr Mullen was the victim. He was stabbed. He has no reason not to tell the truth as best he can. No reason to lie to this jury. What Ryan Mr Mullen told you is that Martin Hay did not assault him but the tattoo guy did.” The jury of eight women and seven men made their choice in less than an hour, returning a unanimous guilty verdict.

Thereafter Ms Healing told the court Hay had five previous convictions involving violence including an assault on a police officer for which he was jailed for 13 months. Other previous crimes include nine separate disorder offences, perverting the course of justice and failure to appear at two court hearings.

It was also revealed that when Hay attacked Mr Mullen he was out on licence having been sentenced to 14 months for carrying a knife.

Sheriff Simon Fraser returned Hay to prison to serve the remainder of his previous sentence and jailed him for a further three years.