A teenager arrested in connection with the murders of two police officers will face no further action, a force said.
The 15-year-old was held on suspicion of assisting an offender following the deaths of Pcs Fiona Bone and Nicola Hughes in Hattersley, Greater Manchester, on September 18.
Assistant Chief Constable Steve Heywood said: "We remain committed to fully investigating the circumstances surrounding the murders of PC Fiona Bone and PC Nicola Hughes.
"As we have said previously, this remains a complex and sensitive investigation and we continue to ask the public to search their conscience and urge anyone who has any information to contact us."
The funerals for the two officers will take place next week.
Dale Cregan has appeared in court accused of their murders.