GardaÍ have now arrested 16 people for withholding information about the savage knife murder of Lorcan O'Reilly.
The respectable 21-year-old was stabbed to death on Halloween but officers have faced a wall of silence as they continue their investigations.
Those arrested for withholding information include women and juveniles.
"Gardaí will keep plugging away on this investigation. It would be a lot more simpler if there was co-operation from key witnesses but this is not happening," a source explained.
"People will continue to be arrested if it is suspected that they witnessed this crime or have information about it."
Lorcan was stabbed to death in Dublin's Oliver Bond Street flats complex at 2.45am on November 1 when he tried to break up a fight.
The chief suspect for the brutal murder is a 16-year-old youth who has close links to gangster 'Fat' Freddie Thompson. This teen presented himself to Kevin Street Garda Station for questioning with his two grandmothers. However, officers declined to take a statement from the teenager.
They intend to collect more evidence before questioning him about the murder.
Since then, it is believed that potential witnesses have been subjected to intimidation.