The funeral has taken place of Mr Matthew Burns, who died on Thursday in Castlewellan, Co Down in a gun attack that also left his brother badly injured.
Father Albert McNally condemned those responsible as inhuman and unjust "dealers in death" and described the attack as a summary execution.
Mr Burns had survived a bomb attack and a paramilitary punishment attempt within the past two years.
Sinn Féin has denied the Provisional IRA killed Mr Burns over alleged drug-dealing, but the PSNI Chief Constable Sir Ronnie Flanagan has not out ruled the possibility.