Summary Cregan pleaded guilty to murdering father and son in separate incidents last year.
LONDON (AP) - A British judge has imposed a life sentence on a man convicted of murdering four people, including two unarmed British police officers in a gun and grenade attack.
Dale Cregan had admitted killing officers Fiona Bone and Nichola Hughes as they responded to a burglary call near Manchester in September.
Prosecutors said the 30-year-old Cregan fired some 30 shots at the officers then lobbed a military fragmentation grenade into the yard of the house as he fled.
Earlier in the trial, Cregan also pleaded guilty to murdering father and son David and Mark Short in separate incidents last year. Prosecutors say those killings stemmed from a feud between two Manchester crime families.
