Police constables Nicola Hughes, 23, and Fiona Bone, 32, who was laid to rest in Moray where she was brought up, were killed on September 18 in Hattersley, Greater Manchester.
Dale Cregan, 29, had previously pled not guilty to murdering the officers and to the murders of Mark Short, 23, in Manchester last May, and his father David three months later.
Amateur boxer Mr Short was gunned down at the Cotton Tree pub in Droylsden, Manchester, on May 25. His 46-year-old father was found dead on August 10 following a blast at a house in Clayton.
Cregan, of no fixed address, appeared by video-link with nine co-defendants at Liverpool Crown Court, three of whom were asked to enter their pleas.
Matthew James, 33, from Clayton, pled not guilty to the murder of Mark Short and the attempted murders of John Collins, Ryan Pridding and Michael Belcher.
Francis Dixon, 37, from Stalybridge, pled not guilty to the murder of David Short, the attempted murder of Sharon Hark and causing an explosion with a hand grenade.
Mohammed Ali, 23, from Chadderton, denied assisting an offender.
All ten were remanded in custody by Mr Justice Holroyde until their trial at Preston Crown Court on February 4.