Two handguns have been recovered from the burnt-out wreckage of a bogus taxi used in a gangland hit on two criminals.
Gardai said forensic experts have been examining the shell of the Audi A6 since it was found abandoned shortly after the murder of brothers Paul and Kenneth Corbally.
And a High Court judge has warned of the need to protect the identity of a 14-year-old boy, under armed guard in hospital where he is being treated for gunshot wounds he suffered in the attack.
The teenager was in the back seat of the Corballys' Lexus when the gunmen struck.
The two dead men were shot several times in the head and body after their Lexus was rammed by attackers on the Neilstown Road, west Dublin, on Monday night.
The silver Audi, which had fake registration plates 00 KE 13498, was stolen in Co Carlow on the night of June 8-9. Its correct registration was 02 D 2633.
It also had a bogus taxi sign fitted to the roof.
Detectives renewed their appeal for information over the killing. They particularly urged anyone who was in the Newlands Road area between 8pm and 8.30pm on June 28 to contact Ronanstown Garda Station.