GARDAI investigating the murder of veteran criminal Eamon Kelly have been given another year to keep DNA evidence taken from two men.
The pair, who were arrested shortly after the killing in 2012 but not charged, had DNA samples taken while they were in garda custody.
Judge Anthony Halpin granted a 12-month extension to detectives to retain the samples for use in their continuing investigation.
Dublin District Court heard there were nearly 1,000 lines of enquiry, and a foreign CCTV expert had been brought in to analyse video evidence.
Kelly was murdered at Furry Park Road, Killester, on December 4, 2012.
He was out walking near his home when he was shot several times.
Sgt Basil Grimes told the court the respondents in the case were arrested on December 8, 2012.
They were detained at Coolock and Raheny Garda Stations on suspicion of possession of a firearm with intent to endanger life and membership of the IRA.
Samples were taken from them while they were in custody.
Permission was granted for sample retention late last year and that was due to run out.
The court heard that another man had already been charged and was due to be tried next year.
Sgt Grimes said there was DNA evidence linking the respondents to the crime and gardai were hoping to send a "substantial file" to the DPP by the end of this year or the beginning of next year.
The investigation included just under 1,000 lines of enquiry.
The CCTV expert involved had had to come from another jurisdiction to analyse the footage.
The murder weapon was "still outstanding" and was considered to be an integral part of the investigation, the court heard.
There was evidence that one of the two respondents had access to a car that gardai believe was used in the killing.
John Bermingham, the solicitor for one of the men, said the issue of the murder weapon being found was a "red herring" and had not been a bar to prosecution in the case of the man who was charged.
Solicitor Michael Hanahoe, for the second man, said there was "nothing new" in the State's application.
He said the prospect of the murder weapon being retrieved was "more hope than expectation".
Sgt Grimes said the CCTV expert had only become involved since the last time an extension was granted.
Judge Halpin said it was accepted that murder cases required a "very high standard of investigation" and this took time.