Two dissident republicans have been jailed for the murder of Constable Stephen Carroll, who was shot by the Continuity IRA in 2009.
Brendan McConville and John Paul Wootton must serve a minimum of 25 years and 14 years in prison respectively, Lord Justice Paul Girvan said.
The pair had already been found guilty of murdering the Police Service of Northern Ireland (PSNI) officer in Craigavon, County Armagh.
After answering a 999 call, Constable Carroll was shot in the back of the head by a gunman who fired through the window of his unmarked police car.
The 48-year-old was the first policeman to be killed by republican terrorists since the peace process reforms which saw the Royal Ulster Constabulary replaced by the PSNI.
The judge told Belfast Crown Court: "The killing comes at a time when terrorist activity has thankfully substantially decreased and it has been wholly rejected, as demonstrated by the will of the people.
"Any terrorist who continues to activate that terrorism at this point in time must be deterred from continuing in that course and any sentence must reflect that need for deterrence," he said.
Lawyers for 41-year-old McConville and 25-year-old Wootton presented mitigating factors to Lord Justice Girvan.
The pair, who had grown beards as part of a no-wash protest by dissident republican inmates at Maghaberry prison, showed no remorse, the judge said
Constable Carroll's widow Kate said she was disgusted with the sentence.
"It gives the message out that it is fine to kill a policeman here because you get a rap on the knuckles," she said.
"Justice has been done? Not for us it has not. Stephen is still in his grave."
She attacked the difference in sentencing between Northern Ireland and England, where killing a policeman can receive 30 years in prison.
"It should be the same everywhere. You cannot make exceptions in one country. It is disgusting," she said.
A statement on her behalf read to the court said: "I feel that I have not only had my soul mate, best friend and future taken away from me, but I did not even get a chance to say goodbye properly.
"Stephen was my life and religion and losing him was heart-breaking, gut-wrenching."
Wootton, who had attempted to get the address of another policeman weeks before the murder, was also convicted of collecting information for the use of terrorism.
His mother, Sharon Wootton, was handed a 12-month suspended sentence for removing computers linked to her son from their home
The shooting occurred two days after two British soldiers were murdered in a Real IRA gun attack outside their barracks in Antrim town.