The victim was not known to Gardaí
Gardai are questioning a man in connection with the murder of Conor O'Brien in Co. Meath.
The man, who's in his 50s, was arrested in Carlow on Tuesday for possessing a handgun.
However yesterday evening, Gardai said he had been arrested in relation to the murder of Mr. O'Brien.
The 19-year-old, who was originally from Gorey in Wexford, was shot and killed in Enfield last Thursday.
He was not know to Gardai, who described him as someone who "kept to himself".