The family of Joseph Rafferty, who was shot dead by a former member of the IRA in Dublin last year, has met the US special envoy for Northern Ireland just ahead of a trip to the US.
Mr Rafferty's sister Esther Uzell last night said two Sinn Féin elected representatives had information on the killing which they had not given to the Garda. She believed if it was, it would result in an immediate arrest.
She was "very pleased" with how yesterday's talks in Dublin had gone between her family, Mitchell Reiss and US ambassador James C Kenny.
"He [ Mr Reiss] listened to everything we had to say and I'm very confident that he will be able to help us . . . we discussed a lot of the evidence about Joseph's murder which we have already discussed with the Independent Monitoring Commission."
Ms Uzell, her brother-in-law Bart Little, her sister Sandra and Fianna Fáil councillor Gary Keegan will travel to the US for a week on Saturday for a series of meetings with US politicians.
Mr Rafferty, a father of one, was gunned down last April in the Ongar housing estate in west Dublin. He was originally from the south inner city.
In the months leading up to his murder, he had become embroiled in a dispute with a family from the south inner city. The dispute had its roots in a fight the previous October at which three brothers from the area assaulted two members of Mr Rafferty's family.
Mr Rafferty was told a number of times that he would be "got" by the IRA.