The murder of Constable Stephen Carroll in Craigavon, County Armagh, has been widely condemned.
FIRST MINISTER PETER ROBINSON
This is a battle of wills between the political class and the evil gunmen - the political class will win.
We are absolutely determined that these people will not direct us, will not frame our agenda, and will not cause us to retreat from the steps that we believe to be right to take this country forward, so we are moving forward.
I am glad that every party in the assembly is solidly in support of the chief constable, is solidly of the view that we should not turn back from that which we have put our hand to, that's the kind of unity that can defeat anybody.
DEPUTY FIRST MINISTER MARTIN MCGUINNESS
We are going to remain united in our approach and ultimately we will prevail.
These people are traitors to the island of Ireland, they have betrayed the political desires, hopes and aspirations of all of the people who live on this island.
They don't deserve to be supported by anyone.
SECRETARY OF STATE SHAUN WOODWARD
It may be that this small number of criminals do regrettably have the capacity, at the moment, to take away life, but what they will never have is the capacity to take away from people the peace process and the political progress that's been made.
My job and every politician's job in Northern Ireland is to give the people of Northern Ireland what they want, which is freedom, the rule of law and democracy - and we will do that.
CHIEF CONSTABLE SIR HUGH ORDE
I reassure the whole community that we will not be found wanting.
We have two major inquiries, fully-resourced, running at the minute and we will pursue those responsible for the murder of the two soldiers, the two young soldiers, and indeed my own officer last night to the ends of the earth.
We do appeal for any assistance in that from anybody who has any information at all, however small, to step forward, be brave, and tell us what they know, because collectively I am clear we will solve these crimes.
DOLORES KELLY, SDLP UPPER BANN ASSEMBLY MEMBER
We are staring into the abyss.
There is little point appealing to the people who planned and did this, but all of us have to realise we are on the brink of something absolutely awful. All of us have to get together to pull ourselves back from the brink.
ULSTER UNIONIST DEPUTY LEADER DANNY KENNEDY
These terrorists seem totally incapable of understanding that they are flying in the face of the overwhelming will of the people in Northern Ireland, Great Britain and the Republic of Ireland who want peace and political stability.
They will discover that the political parties and people of Northern Ireland are determined in their collective resolve to withstand any and every assault on the democratic institutions that have been in place for the last decade.
JOHN O'DOWD, SINN FEIN ASSEMBLY MEMBER
It is a tragedy, it is a complete waste.
But I believe that there is an alternative, that there is a peaceful way forward. It's not easy, politics is not easy, but it's much better than what we witnessed last night.
ALLIANCE LEADER DAVID FORD
I simply cannot comprehend the sheer evil of those involved in this attack.
This shooting was cowardly and despicable. This murder must be roundly condemned by all right-thinking people. It is clear that dissident republicans are determined to attempt a sustained attack on peace and stability in Northern Ireland.
TAOISEACH BRIAN COWEN
As with the murders in Antrim, this callous crime is an attack on the Irish people and the peace we have all worked so hard for.
The people and all of their democratic representatives reject this violence and will overcome the evil and unrepresentative minority who want to drag us back to the past. Violence and hatred will not triumph over peace and democracy.
DAVID SIMPSON, DUP UPPER BANN MP
What we have seen over the last 36 hours is a deliberate and sustained effort by terrorist murderers to try and drag Northern Ireland back to the worst days of Ulster's past.
I utterly and completely condemn the criminals responsible for this latest outrage and I hope that the vermin responsible for it are brought to justice immediately.
JIM ALLISTER, TRADITIONAL UNIONIST VOICE
Having turned our police into a mere service and deliberately destroyed Special Branch, all at republican behest, we are now ill-equipped to face the harvest of what has been sowed.
Our present reduced and denuded police cannot cope alone with active republican terrorism. Thus, now is the time to bring in the SAS, before it gets out of hand.
PROFESSOR SIR DESMOND REA, POLICING BOARD CHAIRMAN
For a police officer to be shot in such a cold, callous and cowardly way when protecting the community is something which will be condemned by all right thinking people.
It must not be allowed to hinder the peace and political progress being made in our society.
PRESBYTERIAN MODERATOR, RT REV DR DONALD PATTON
This outrageous and senseless attack by a few people intent on taking us back into the past must not and will not deflect the vast majority who will continue to work hard to move us into a peaceful and positive future.
TERRY SPENCE, POLICE FEDERATION NI CHAIRMAN
Our colleague died doing his duty simply because he was a uniformed symbol of the law and order which protects society from the criminal few who would drag us back into the morass of a bloody past.
They will be defeated only when the responsibilities of democracy are fully shouldered by all.
SHADOW NI SECRETARY OWEN PATTERSON
This killing is brutal and will not achieve its political aims. It is vital that everybody helps bring these evil murderers to justice; they must not be allowed to divert us from the great progress made in recent years.
REV AIAN FERGUSON PRESIDENT OF METHODIST CHURCH IN IRELAND
The action of those who murdered this constable stands in marked contrast to the unanimity of feeling and determination expressed by all those at today's Assembly and which reflected the mind of the electorate.
RT REV HAROLD MILLER, CHURCH OF IRELAND BISHOP OF DROMORE; MOST REV JOHN MCAREAVEY CATHOLIC BISHOP OF DROMORE
The cold-blooded murder of a policeman who has served the community for 20 years, while doing his duty in Craigavon, was a morally bankrupt act.
Those who perpetrated this murder and other recent atrocities have nothing to offer the future of our society. Their 'god' is destruction.
FACHTNA MURPHY, GARDA COMMISSIONER
The murders carried out in the last number of days in Northern Ireland represent a serious attack on the fundamentals of democracy itself and An Garda Siochana will do everything within its power to assist and co-operate with the Police Service of Northern Ireland to bring those responsible to justice.