The criminal was targeted by two gunmen who also killed innocent plumber Anthony Campbell who was working at a house in Finglas.
Gardai have carried out over 800 enquiries to date and arrested 14 people.
But they say the investigation cannot continue without new information.
Between 9am and 9:30am on the morning of December 12th 2006 two gunmen arrived at the house in Scribblestown Park in Finglas where Marlo Hyland has been staying.
They opened fire on the 39-year-old in his bed killing him instantly.
They then went downstairs where they shot 20-year-old apprentice Anthony Campbell who was doing a small plumbing job.
He was shot dead because the gang feared he could have been a vital witness against them.
At the inquest today relatives of Marlo Hyland have been giving evidence.
His niece Elaine Hyland said he was very paranoid before he died, he kept a samurai sword in his room and was reluctant to answer the door.
His brother William said Marlo had been threatened and was depressed and not eating.
Detective Inspector Ciaran McInerney told the Coroner’s Court that sinister criminal elements were behind the double murder and the apprentice plumber was eliminated by two gunmen with murderous intent.
The Court has heard that despite 800 Garda enquiries, 590 witness statements and 14 arrests the investigation cannot continue without new information and so has effectively stalled.
