A violent criminal living abroad is being treated as a suspect for the murder of Deirdre Jacob 20 years ago, it has emerged.
Gardaí stressed that they have extensive inquiries yet to carry out, including interviews with people suspected of withholding information as well as possible searches.
Officers will not be able to seek the man’s extradition unless there is enough evidence to convince the DPP to initiate charges.
Sources said that only then could gardaí seek a European arrest warrant and bring the individual before the courts.
Ms Jacob, an 18-year-old student, disappeared from the entrance to her home, on the outskirts of Newbridge, Co Kildare, on July 28, 1998.
It was announced yesterday that her case, which was a missing person’s investigation, had been upgraded to a murder probe.
The suspect has a record of serious sexual violence against women and has been linked to other murders. The Irishman was considered by gardaí to have planned his crimes and to be forensically aware.
It is not clear where the man is living, but some sources indicated he was resident in the UK.
Gardaí said they now believe Ms Jacob was murdered “on or after” July 28.
Chief Superintendent Brian Sutton, who is leading the investigation, said that the decision to upgrade the case to a murder inquiry followed a major review of over the last 12 months.
This was conducted by gardaí from the Kildare division as well as from the Serious Crime Review Team, the national cold-case unit.
Chief Supt Sutton said the decision did not stem from “one bit of information”, but was the result of the review and the receipt of new details following the 20th anniversary appeal last month.
“We pulled apart the missing person investigation and put it back together and as a result of that there are new lines of inquiry and, apart from that, new information came to light,” he said.
“There are several lines of inquiry,” he said adding: “Yes, there are persons of interest that we need to look back at.”
He declined to go any further on the persons of interest in case it hindered the investigation.
Persons of interest include suspects for the murder, but also people thought to be withholding information in relation to it, including people who have previously given false or incomplete statements.
Chief Supt Sutton said there were people who gave information at the time who will be asked if they have any further information and interviews will also be carried with people not previously spoken to. He said they may also reexamine CCTV and house to house inquiries.
He said information had to be “corroborated” and “cross-checked”.
Some 3,000 inquiries have been conducted so far and 2,500 statement taken.
Chief Supt Sutton said: “We may need to conduct searches, but we will check out everything first.”
He confirmed inquiries were being conducted “domestically and abroad”.
But the senior officer cautioned against expectations of early breakthroughs: “This investigation is going on 20 years, there’s isn’t going to be an instant fix.”
Ms Jacob’s father Michael praised the work of gardaí but said that it was “heartwrenching” to hear Deirdre had been murdered.
He hoped the upgrading of the investigation and the media coverage would encourage those people with information to come forward.
Gardaí have previously investigated if one killer may have been behind the disappearances of three of seven women who went missing in Leinster during the 1990s, including Ms Jacob.
Those with information can contact Kildare Garda Station on 045 521222 or the Garda Confidential Line 1800 666 111
This story first appeared in the Irish Examiner.