Hamid Sanambar came to Ireland in his 30s, having successfully applied for political asylum here.
The 42-year-old Iranian national had lived in various parts of the country, including Longford and Cork city, but at the time of his murder on Tuesday had an address in Priorswood, Clonshaugh, Dublin 17.
Sanambar had become more involved in gun attacks in the past 12-18 months. He had been warned by the Garda that his life was in danger from other gangland criminals.
He was believed to have lured drug dealing associate Sean Little (22) to north Co Dublin where he was shot dead last Tuesday week at the behest of a Finglas drugs gang.
Gardaí are also trying to establish if he was involved in the murder of Jordan Davis (22) in Darndale, Dublin, the following day. He was also linked to two other shootings in Dublin in which men were wounded.
Sanambar was given a three-year suspended sentence in 2015 for his role in the violent robbery of two women working in a Cork brothel in 2012.
Cash, laptops and mobile phones to the value of about €5,000 were stolen and one of the women had her jaw broken. Sanambar, who had facial tattoos, carried out that robbery with Irish men he claimed to have met road bowling while living in Cork about eight years ago.
