There was an armed police escort as Dale Cregan and nine other defendants were brought to Preston Crown Court early this morning.
A helicopter flew above the large convoy as four prison vans brought the defendants from Manchester jails and elsewhere.
Around 150 police officers are involved in tight security throughout the court complex because of the large number of defendants and high interest in the case.
All staff and members of the public must go through airport style metal detectors set up in portacabins.
Dale Cregan is accused of the murders of PCs Nicola Hughes and Fiona Bone as they responded to reported burglary in Hattersley last September.
Cregan's also accused of the murders of amateur boxer David Short and his father Mark Short last year.
Cregan's co-accused are variously charged with helping or taking part in the murders of David and Mark Short, firearms offences or assisting an offender. All ten will face a jury trial, having previously pleaded not guilty to all charges.
Cregan, Leon Atkinson, 35, from Ashton-under-Lyne, Luke Livesey, 27, from Hattersley, Damian Gorman, 38, from Glossop, Ryan Hadfield, 28, from Droylsden, and Matthew James, 33, from Clayton, are all accused of the murder of Mark Short and the attempted murders of three others in the pub at the time - John Collins, Ryan Pridding and Michael Belcher.
Accused of the murder of David Short are Cregan, Francis Dixon, 37, from Stalybridge, Anthony Wilkinson, 38, from Manchester, and Jermaine Ward, 24. All four are also jointly accused of the attempted murder of Sharon Hark on the same day, and a single charge of causing an explosion.
Wilkinson is additionally charged with possession of a firearm with intent to endanger life and Mohammed Ali, 32, from Chadderton, Greater Manchester, is accused of assisting an offender.
Cregan alone is charged with the murder of the two police officers.
The process of selecting a jury began this morning, the prosecution is expected to open its case on Thursday.