A brutal, thuggish act, outside a pub in Belfast's Markets district on January 30th became the catalyst yesterday for an extraordinary outpouring of sentiment at every level in Washington against the continued existence of the IRA.
The arrival of the McCartney sisters on Capitol Hill was a sensation, with a huge media contingent packing the corridors outside as they told the story of Robert McCartney's murder in a congressional office to senators Edward Kennedy, Hillary Clinton, John McCain and Chris Dodd.
Senator Kennedy, one of the first members of Congress to help bring Gerry Adams in from the cold in Washington 10 years ago, afterwards expressed the frustration of US supporters of the Northern Ireland peace process at recent events.
It had been 11 years since the IRA ceasefire and seven years since the Good Friday agreement, he said.
"No political party could any longer have an armed unit that continues the violence and criminality.
He said he personally believed Mr Adams wanted to see the IRA disbanded.
"But I think there's a time to hold 'em and a time to fold 'em and it's overdue in terms of the disbandment of the IRA."
Sinn Féin could not be a fully functioning democratic party "with the albatross of the IRA around its neck", he told a packed press conference with the five sisters, Catherine, Claire, Donna, Paula and Gemma, and the murdered man's fiancée, Bridgeen Hagans.
"I think he understands that hopefully and he has responsibilities for that."
The McCartney sisters will be honoured guests at the White House today where president George Bush is expected to echo the calls for the IRA to disband.
"I'm looking forward to meeting these very brave souls," Mr Bush told reporters yesterday.
"They've committed themselves to a peaceful solution. And hopefully, their loved one will not have died in vain. I mean, hopefully, some good will come out of the evil perpetuated on this family."
The idea that the murder could hasten the end of the IRA was also touched upon by senator Chris Dodd.
The courage of these "remarkable sisters" had "given us all some glimmer of hope that maybe we can end this violence once and for all," he said.
Senator Dodd, a long-time supporter of Mr Adams, went on: "It's been too long, too long, it's no longer an excuse, when you consider all the gains that have been made in terms of bringing about an opening in the political process which was denied to too many members of the nationalist community for too many years.
"We have not achieved those goals just to say to people that they cannot step forward and give evidence in a murder - a murder - not a political act."
Senator Hillary Clinton said the women were "sending a clear signal that no other person should be murdered and have the murderers walk free".
She said they had told her that "going to the police now is something that people in both communities do but to say that that cannot be done here flies in the face of evidence that it is being done - it is being done for example in the case of a Sinn Féin member's son who was murdered and the family went to the police and rightly so".
On behalf of the family Catherine McCartney made a short statement saying: "We came here to tell the story of Robert's murder and we know we have the support of the senators.
"We hope this will produce justice for the family."