Dale Cregan, the man who has already admitted murdering policewoman Fiona Bone – who grew up in the island – and her colleague Nichla Hughes, has admitted the murders of a father and son.
Mark Short, aged 23, was shot in a pub in Droylsden, Greater Manchester, in May 2012. His father David, 46, was killed in a gun and grenade attack in nearby Clayton last August.
Cregan, aged 29, changed his plea on both counts to guilty at Preston Crown Court.
In February, he admitted the murders of Greater Manchester Police officers Fiona Bone and Nicola Hughes.
Fiona’s family live in Port St Mary.
The trial heard how David Short was fatally injured when Dale Cregan and Anthony Wilkinson attacked him at his home on August 10. Cregan admits causing an explosion, but denies the attempted murder of Sharon Hark later that day.
Earlier in the trial, the jury heard that in September Cregan lured PCs Bone and Hughes to a house in Mottram before shooting them repeatedly and throwing a grenade.
Cregan also offered guilty pleas on three charges of attempted murder of three men in the pub attack - John Collins, Ryan Pridding and Michael Belcher.
There are nine co-accused still on trial in connection with the murders of David and Mark Short. They deny the charges against them.