A national witness protection scheme should be created to encourage more supergrasses and vulnerable witnesses to come forward, police chiefs have said.
The Association of Chief Police Officers said the scheme, which could be brought in under the new National Crime Agency, would offer a more consistent approach under the lead of a senior chief constable and outside of local forces.
The recommendation follows calls for police to be given better training to protect vulnerable witnesses after the gangland killings of a middle-aged Lincolnshire couple in 2004.
Andy Cooke, the assistant chief constable of Lancashire Police, said: "Britain is the only country in Western Europe without a national witness protection scheme and you need a system that people have faith in. We had a patchwork response across the country where levels of protection differed. Witness protection is under-used and if there was a national service people would be encouraged to use it."
The scheme would also increase transparency to make it easier for people in witness protection to make complaints, bring in an independent oversight and review process, and a declaration of the minimum obligations expected from authorities and witnesses.
John and Joan Stirland were found shot dead at their bungalow in the Lincolnshire village of Trusthorpe on August 8, 2004.
An inquest at Lincoln Crown Court heard the shooting was a "revenge" attack after Mrs Stirland's son, Michael O'Brien, shot Marvyn Bradshaw, 22, dead outside a Nottingham pub in August 2003. The "criminal community" in Nottingham believed the bullet was meant for a friend of Mr Bradshaw.
Nottingham crime boss Colin Gunn, who had persuaded police officers to provide him with information, and two other men were convicted of conspiring to murder the couple in 2006.
The inquest in February heard that, despite Mrs Stirland speaking to her family liaison officer shortly before 2pm on August 8 to report a stalker, the couple did not receive a visit from Lincolnshire Police until 9.30pm that evening. By that time the couple were both dead. Mr Stirland, 55, had been shot six times in the chest. His 51-year-old wife, a nurse, suffered four gunshot wounds.
The jury in the inquest found Nottinghamshire Police failed to share intelligence about the threat posed to the couple by Gunn's gang, but it cleared Lincolnshire Police of failing to protect the couple.