No police officers will be charged with criminal offences following an independent investigation into the murders of a Nottinghamshire couple.
The Stirlands were shot dead at their seaside bungalow
John and Joan Stirland were shot in their Lincolnshire bungalow in August 2004 in gangland-style murders.
The Independent Police Complaints Commission looked at the communication between Notts and Lincs police to see if enough was done to protect the pair.
The Crown Prosecution Service (CPS) said it would take no further action.
Mrs Stirland had reported seeing a prowler several hours before she was killed.
Three men, including Nottingham crime boss Colin Gunn, were given life sentences for the murders.
The CPS was asked in May by the IPCC to consider if there was enough evidence to prosecute any police officer for misconduct.
The IPCC will now begin a separate inquiry into whether any police officer should be disciplined, with the investigation focussing on up to eight officers from Nottinghamshire Police.
Len Jackson, IPCC Commissioner, said: "Following this CPS decision, I will now make my recommendations to the forces involved concerning potential misconduct issues.
"There remain some complex issues to be addressed in this matter but given the length of time this whole process has taken, I am keen that matters should be resolved as quickly as possible for all concerned."
Mr Stirland, 55, and his 51-year-old wife were forced to flee Nottingham after a gun attack on their former home. They moved to Trusthorpe, where they were killed eight months later.
During the murder trial in 2006, the court heard the motive for the killings was revenge for a murder carried out by Mrs Stirland's son, Michael O'Brien in Nottingham in 2003.
Colin Gunn, 40, was jailed for 35 years conspiracy to murder in 2006.
Michael McNee, 21, of no fixed address, was jailed for at least 25 years and John Russell, 29, of Northcote Way, Nottingham, was jailed for 30 years, both for conspiracy to murder the Stirlands.