Theresa Villiers says paramilitaries' 'violent and brutal' actions are 'unacceptable'
Secretary of State Theresa Villiers has told MPs it is unacceptable that paramilitary killings are still taking place in Northern Ireland.
She described Michael McGibbon's widow Joanne as "incredibly brave".
The father-of-four died after being shot in north Belfast on Friday night.
Speaking in the House of Commons, Ms Villiers said the circumstances of Mr McGibbon's murder were "deeply tragic and heartbreaking".
In reply to a question from the DUP's Nigel Dodds, Ms Villiers said everyone should join Mrs McGibbon in condemning the murder.
She said it was "utterly unacceptable that in modern Northern Ireland there are still people who believe they can take the law into their own hands and administer this violent and brutal treatment".
Michael McGibbon, 33, was shot three times in the leg in what the PSNI described as a paramilitary attack.
He was taken to the Royal Victoria Hospital in Belfast, where he later died.
Police said Mr McGibbon was not known to them and they did not know why he had been murdered.
Speaking at a vigil held at Holy Cross Church in Ardoyne on Tuesday, Joanne McGibbon said the Ardoyne community is stronger than those who carried out Michael's killing.
"The strength of this community will overtake anything that anyone who wants to destroy it has to do.
"If we all stay strong, we can stop these people. They can't beat us and it's not fair that families should have to go through this. They are not judge and jury."
In a tweet, the PSNI said a loyalist protest, which had been planned for Tuesday night, was cancelled out of respect for Mr McGibbon's family.
The Rector of Holy Cross, Fr Gary Donegan, said the vigil sent out a strong message to Mr McGibbon's killers.
"We're a proud community here. A community that has suffered and endured loss like no other in the history of this country," he said.
"We have the home of Michael in the shadow of this church, but it was people who came from the shadows who chose to take his young life.
"We will not let those who live in the shadows empty us of our courage.
"This young widow showed more courage, compassion and mercy than you'll ever know."