The Assembly is today set to unite to condemn the Massereene murders.
First Minister Peter Robinson and deputy First Minister Martin McGuinness, who have postponed their trade mission to the US which was due to begin today, are expected to make a statement to MLAs.
And, while the Speakers Office has still to give the go-ahead, there could be a debate on the attack.
The DUP leader and Sinn Fein deputy chief separately voiced sympathy to the victims’ families and said the attempt to destabilise the four-party coalition at Stormont would not succeed.
In a statement which took more than 12 hours to emerge, Sinn Fein President Gerry Adams said the attack was “wrong and counterproductive” but added there are elements within unionism and within the British system that do not want the peace process to achieve its objectives.
He and Mr McGuinness appealed to republicans to hold their nerve and not be deflected from their objectives. Condemnation of the attack was led by Gordon Brown and Ulster Secretary Shaun Woodward, and echoed by the Taoiseach Brian Cowen.
Ulster Unionist Danny Kennedy said his party would be watching closely “and evaluating the reactions of all political leaders and parties to this indefensible act”.
Alliance leader David Ford said it highlighted the real need for an intelligence-based approach to tackling terrorism.