The trial of a man accused of the murder of two police officers is set to open with the jury being told details about the double-killing for the first time.
One-eyed Dale Cregan, 29, is accused of the murders of Pcs Nicola Hughes, 23, and Fiona Bone, 32, in a gun and grenade attack on September 18 last year.
Family of the two murdered officers are also expected to attend Preston Crown Court for the first time as the trial begins in earnest.
Cregan also stands accused of the murder of David Short, 46, and his son, Mark, 23, in the months before the attack on the officers.
Nicholas Clarke QC, prosecuting, will lay out in detail the case to the jury against Cregan and nine other defendants.
Cregan's co-accused are variously charged with helping or taking part in one of the four murders, attempted murder, firearms offences or assisting an offender.
Around 150 police, some armed with machine guns, will patrol in and outside the court complex amid tight security for the trial, expected to last up to 12 weeks.
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 - 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.