A handgun used in the murder of a senior IRA man in Belfast was "extremely rare" and came from eastern Europe, police have said.
Gerard 'Jock' Davison, 47, was shot dead at Welsh Street, in the Markets area at 09:09 BST on Tuesday 5 May.
A gunman shot him from behind before standing over him and shooting him four more times in the head.
A senior police officer told the BBC Crimewatch programme that the gun and bullets were unusual.
"The weapon and bullets used were an eastern European type called Makarov," Det Supt Kevin Geddes said on the programme.
"These 9mm bullets are unusual in as much as they will not work in most types of western handgun.
"They are a slightly different size and can only be fired using a Makarov type gun.
"This type of weapon and ammunition are extremely rare in Northern Ireland."
Witnesses to the shooting said the gunman was 5ft 6in tall and was wearing a dark, hooded rain jacket. He escaped up an alleyway towards Stanfield Place.
"We need to know where he went next. We are also issuing a photo of a similar type jacket in the hope this may jog someone's memory," Det Supt Geddes said.
Police believe the gunman may have been standing at the junction of Welsh Street and McAuley Street shortly before the shooting.
A man was also seen with a red and white carrier bag, holding it with two hands on Welsh Street.
Police also appealed to anyone who parked a car in the Markets area between 08:00 BST and 09:00 BST on that Tuesday, and then walked to work, to contact them.
Police have said they do not believe dissident republicans were behind the attack, and do not believe Mr Davison's murder was sectarian.
So far, three people have been arrested over the murder, but all of them have been released without charge.
It is understood Mr Davison was involved in the fight in a Belfast bar in January 2005 that led to the death of Robert McCartney. It was one of Northern Ireland's most high profile killings.
Mr Davison's uncle, Terence, was later acquitted of Mr McCartney's murder.
Crimewatch was broadcast on BBC One Northern Ireland on Tuesday at 21:00 BST and is available on BBC iPlayer