The sisters of a man who was murdered in Belfast are meeting the US President George Bush.
They claim Robert McCartney was stabbed and killed by the IRA after an argument in a bar on 30 January. They want the people who killed their brother caught.
Mr McCartney's family accuse the political party Sinn Fein of a cover up, as some members were in the bar at the time but didn't go to the police.
The family, and Mr McCartney's fiancÚ, are meeting Mr Bush at the White House.
The Irish Prime Minister Bertie Ahern will also be at the reception which will mark St Patrick's Day on Thursday.
Sinn Fein leader Gerry Adams
Sinn Fein is one of Northern Ireland's main parties, lead by Gerry Adams.
The party has links with the IRA but says it doesn't believe in violence or criminal acts.
The IRA is a republican organisation. For years it carried out bombings and killings to try to force the British Government to allow Northern Ireland to join the rest of Ireland.
Five years ago it agreed to start getting rid of its weapons, as part of the peace process.
The party has had a lot of support in the United States, but the McCartney sisters' claims could change that.
Many Americans are now saying it's time for Sinn Fein to cut all its ties with the IRA.
Some political parties have even said they won't have anything more to do with Sinn Fein until they do this.