A pub drinker who left a man with long-term scarring when he glassed him in the face in an “act of senseless violence” has been jailed for 15 months.

Steven Merrick had been drinking when his mood suddenly changed in the Cat and Wheel public house in Cheltenham Road, Montpelier, and he smashed his glass into the face of Oliver Jones.

The 28-year-old defendant, of Oaktree Crescent, Bradley Stoke, then fled, leaving Mr Jones bleeding from cuts to his left cheek and left eye area.

Merrick was not arrested until nine months later, after a painstaking police investigation led to him being identified by Mr Jones’ partner who had been with him when he was attacked.

He later pleaded guilty to a single offence of wounding.

Mark Hollier, prosecuting, said Mr Jones was left with a cut near his left eye and another to his left cheek after Merrick smashed a glass against his face on the evening of February 23 last year.

He said Mr Jones had been enjoying a quiet evening with his girlfriend in the Cat and Wheel pub when the defendant walked in with friends and the two men struck up a conversation.

He said it was not known why Merrick’s mood changed but he said Mr Jones had told the defendant he came from the Lake District originally and it had been suggested the defendant “was a bit thick” as he did not know where that was.

“The defendant suddenly changed his demeanour completely. He swore at Mr Jones and smashed a glass into his face. It came from nowhere,” said Mr Hollier.

As Mr Jones’ face bled the court heard Merrick left the pub with two friends. He said police stopped the defendant’s friends that evening but not Merrick. However after studying CCTV footage and through processes of analysis the defendant was arrested nine months later.

Ian Kelcey, defending, said his client had no previous convictions and was genuinely remorseful. He said Merrick had fallen into a “pattern of drinking” and that day had drunk too much and responded to his victim in a way he now found difficult to understand.

Mr Kelcey said Merrick had written a letter of apology to his victim.

Jailing Merrick for 15 months, Judge Simon Darwall-Smith told him: “The fact it didn’t go into the victim’s eye is by good chance,” he said.

Afterwards, the officer in the case, DC Sam Donati of Bristol CID described the offence as a “vicious and entirely unprovoked attack on an innocent victim.”

He added: “What began as an act of senseless violence has left the victim with long-term scarring and a lasting effect on his self-confidence.”

He said investigation into the crime had been “lengthy and complex” with all possible investigative methods used to track down and prosecute Merrick.

DC Donati credited the victim’s partner for identifying Merrick in an identification parade nine months after the attack.