Detectives investigating an assault at a fast food outlet in Selly Oak last year have released CCTV footage of the moment the victim suffered a jaw-breaking punch to the face.
The 23-year-old is seen backing away from his attacker outside Pizza Land on Bristol Road on 25 February 2012.
Still images were released as part of an appeal in May last year and officers have been following up numerous lines of inquiry ever since.
But despite extensive enquiries, they are still no closer to finding the person responsible.
Officers have now taken the decision to release moving footage of the attack and are urging anyone who recognises the offender to come forward.
Detective Constable Louise Corcoran, from Force CID, said: “This was a serious unprovoked assault which left an innocent man knocked out cold and requiring surgery.
“The offender walked into the shop and made an offensive comment to him before hitting him in the face.
“It’s had a lasting effect on the victim, who has been left physically and emotionally scarred by the assault.
“We need to catch the person responsible and ensure justice is done.”
Anyone with information should call Force CID on 101 or the independent charity Crimestoppers anonymously on 0800 555 111.
Serious violent crime across the West Midlands is down 5.4% to date since April 2012 compared to the same period the previous year, which equates to 113 fewer victims.
For advice on staying safe when out and about visit www.safer-streets.org.