A MAN accused of being part of a gang of "laughing assassins" that gunned down both a policeman and a nightclub bouncer had warned he would shoot someone, a court was told.

The policeman, PC Patrick Dunne, had moved from Bolton to London to become an officer with The Met after quitting his job as head of maths at the Deane School.

He was shot seconds after nightclub bouncer William Danson, aged 31, was gunned down and killed on October 20, 1993.

Gary Nelson is alleged to have fired the fatal shots that killed the unarmed PC and Mr Danso.

Nelson denies two charges of murder.

PC Dunne, aged 44, had been called to a minor domestic dispute, but went to investigate after hearing a series of shots nearby.

He was struck in the chest by at least one bullet and died instantly.

The day before the double killing, Nelson, aged 36, had gone to a mobile phone and car alarm shop where Danso worked as a part-time security guard, Woolwich Crown Court heard.

After being told he could not go into the shop's office, owner Eugene Djaba, went to 'calm him down'.

Mr Djaba, aged 39, spoke via a live video link from Ghana. He claimed that Nelson told him that if the security guard who was working that day had tried to stop him he "would have shot him in the belly".

The defendant then pulled a gun out of his jacket, it was alleged.

"He showed me the gun, told me how many bullets the gun carried," Djaba said.

"It was fully loaded."

The jury has heard that three men ran off laughing loudly after Pc Dunne was shot.

The five woman and seven man jury was also told that on the day PC Dunne and Danso died, Nelson was involved in an argument at the shop.

Danso, who was also known as 'Kwame', was working that day when two men named Blue and Tony started to argue with each other.

Djaba said Tony went inside the shop and made a phone call.

About five minutes later, Nelson who was nicknamed Tyson, arrived.

Danso 'held back' Tony and Nelson until Blue and his friends left.

The security guard then let the pair go, it was said.

Djaba said he learned from Danso, who also worked at the Brixton Academy, that the defendant had been banned from entering the club.

The trial is expected to last five weeks.