Detectives hunting the killers of a German backpacker have travelled to Scotland in an attempt to piece together her final movements.
Inga Maria Hauser was last seen alive 30 years ago, as she journeyed by ferry from Scotland to Northern Ireland on April 6 1988.
The 18-year-old's body was found dumped in a remote part of Ballypatrick Forest on the outskirts of Ballycastle, Co Antrim, a fortnight later.
No one has ever been convicted but police have warned that the net is closing on the killers.
The officer leading the investigation, Detective Chief Superintendent Raymond Murray, said: "The murder was brutal, the attack was brutal and the assault was brutal but there is something horrendously callous about leaving that young girl's body lying unattended in a forest for 14 days.
"All murder is outrageous but that gives another dimension to the horror of that final evening."
Investigators believe that communities in Scotland may also hold vital information about Ms Hauser's movements during her two-day visit before she embarked on the Stranraer to Larne ferry.
A team of detectives handed out leaflets to passengers on board and spoke to those waiting in terminals at Belfast and Cairnryan.
Mr Murray said: "We already know Inga Maria's movements during her journey around England from London to Bath and on to Liverpool. However, we need to know more about what she did and who she met while in Scotland."
Prior to her death, the backpacker travelled around England, from London to Bath and on to Liverpool.
From Liverpool she journeyed to Preston and then northward to Inverness in Scotland. She then took the train to Glasgow and on to Stranraer.
Mr Murray said he wanted to hear from anyone who encountered her.
He added: "I appreciate a lot of time has passed but we need to know places Inga Maria visited."
She cashed £20 worth of traveller's cheques in Inverness.
Mr Murray added: "She will have stood out from the crowd with her German accent and distinctive style of clothing - she was wearing baseball boots and a long, flowing skirt possibly multi-coloured, a jacket, possibly denim with a large blue rucksack. On top of this rucksack was a smaller bag with distinctive US Air Force badge."
Police believe a number of people may have been involved either directly or in the cover-up of what remains one of Northern Ireland's most high-profile unsolved murder cases.
A man in the rural area east of Ballymoney, Co Antrim, was seen soon after the murder with scratches on his face, sparking concern in the community that he was involved.
Police also have a male DNA profile from the crime scene but have yet to secure a positive match.
A number of years ago, in one of the largest DNA screenings ever undertaken in the UK, 2,000 samples failed to produce a definitive match to a male genetic profile found at the murder scene.
However, officers are expecting the results of further testing, including a trawl of updated familial DNA samples, within days.
Mr Murray added: "We have had it from day one.
"It has been run and the scientists have it at the minute and those results are about to come back to the investigation team.
"We are investigators and we keep an open mind but the evidence and the information and the intelligence that we have to date has led us to focus on a very, very small number of individuals."
Mr Murray confirmed that all the suspects were still alive, though he declined to confirm whether they still lived in the north Antrim area.
"They will know who they are," he said.
The senior detective is leading a two-week awareness campaign in a bid to secure the last pieces of the evidential jigsaw.
"I think there are people out in the community who know exactly what happened, I think there are one or two who were possibly involved in the aftermath of this killing," he said.
"I think at least one of them is finding it very difficult to live with.
"We are all getting older, we are moving on - is this something that you want to take with you to your grave?
"Some people are like that, but some people are not, some people struggle and I think this person is struggling.
"It is not too late now to examine your own conscience and come forward to the police.
"What we need is just those few fractional pieces of evidence to help us complete the picture. We think we are close."
He added: "What if this was your daughter or granddaughter - subjected to a brutal and ruthless assault after arriving in a new country before being killed and left in a forest? Think of the fear and pain she felt, think of her family not having justice."
Mr Murray recently travelled to Munich to brief Ms Hauser's sister on developments. Her father Josef is now dead and her mother Almut is battling illness.
"Her father died and her mother in her illness still doesn't know who killed their daughter when she came to visit our land," he said.
"At a time when a lot of people wouldn't come - she did and she ended up paying for that with her life."
Mr Murray appealed for anyone who saw the teenager depart the ferry at Larne to come forward.
She intended to travel to Dublin and had planned to catch a train from the ferry terminal to Belfast before carrying on her journey southward. Instead she was found dead in a forest north of Larne.
"She didn't make it as far as the railway platform and that was her intended destination in the port," said Mr Murray.
The detective also revealed Ms Hauser's poignant last entry in her diary.
He said: "Her last notebook entry on April 6 reads: 'Went from Glasgow to Ayr and from there to Stranraer to get over to Ireland.
"'Saw the sea. Beautiful and mysterious. Wonder where I stay tonight. Need more money.'
"Sadly, Inga's final resting place in Northern Ireland was in Ballypatrick Forest."