Gardaí are questioning a 26-year-old man in connection with the fatal shooting of Wayne Doherty in Dublin.
A 32-year-old father of two, Mr Doherty died after he was shot outside his parents' home in Hartstown on 4 July 2009.
Reports at the time suggested Mr Doherty may have been attacked after confronting a group of men outside his parents' home.
Detectives believe he was the victim of a row that he was not involved in.
