The family of murdered Dublin man Joseph Rafferty has accused Sinn Féin of protecting his killer.
Mr Rafferty, 29, was shot dead outside his home in Ongar in West Dublin last April.
His sister, Esther Uzell, said there are senior Sinn Féin people with information who have not come forward to the gardaí.
She was speaking following a meeting with the US Ambassador at the Embassy in Dublin this afternoon.
The family intends to travel to the US and meet members of Congress to put pressure on Sinn Féin to co-operate with the garda investigation.
However Sinn Féin denies it is harbouring anyone and says it would encourage anyone with information to come forward.
So far gardaí have interviewed over 2,000 people, taken 600 statements and arrested 11 people as part of their investigation.
The family say they know who murdered Mr Rafferty, they know what he is involved in and they know other people have information and they have not come forward.