Police this week arrested the 38-year-old who was acquitted of strangling 12-year-old Kristin Juel Johannessen in 2002.
The man, who was 23 at the time of the murder in 1999 had been arrested in 2000 and sentenced to 12 years in prison the following year.
However, an appeals court ruled that he should be released after his defence lawyers showed that a human hair found on Juel Johannessen's shoulder, which had been put forward as key evidence against him, came from a woman.
Kjell Johan Abrahamsen, the deputy head of the Vestfold Police, told a press conference on Friday afternoon that new DNA techniques had allowed the police to once again tie the murder to the man.
“The reason that the accused was arrested this week is DNA analysis linking the person concerned, in our view, to the murder and to the deceased,” he told Norway's NRK on Friday.
According to Abrahamsen, the new technology opened the way to extracting a DNA profile of the likely murderer from skin cells found under the deceased's fingernails.
“I see it as relatively revolutionary that we have managed to obtain a DNA profile that you would have failed to make just a few years ago,” he said.
Johannessen, from a small village outside Larvik, south of Oslo, was found murdered in a small wood at around midnight on 5 August 1999.
She had cycled off for a swim in the Goksjø lake at 6.30pm that evening, and was reported missing at 9pm.
A 50-year-old man was the first to be charged, and was then acquitted and awarded substantial damages. Shortly afterwards, police arrested the 23-year-old.
Abrahamsen said that police had decided to revisit the case after learning in February that the Norwegian Institute of Public Health (NIPH) had developed a new method for obtaining DNA profiles from skin cells.
The Vestfold police quickly realised how this could help them prove that he had in fact carried out the murder, he said.
They decided to take in the man who had been acquitted in 2002, arresting him on a minor drugs charge, and then using the opportunity to obtain a fresh DNA sample to match against tissue samples removed from under Juel Johanessen's fingernails.
“I do not hide that fact that in May we took the opportunity to obtain the accused's DNA legally,” Abrahamsen said.
The suspect's defence lawyer Søren Hellenes warned that it was too early to draw conclusions on the strength of the new evidence.
“It is clear that in a case like this, where in the last round there was an acquittal based on a faulty analysis of the technical evidence, it is important to review the analysis very carefully,” he said.
On Friday a court ruled that the man could spend four months in remand prison. He continues to deny any involvement, although Abrahamsen said he did not think he would be acquitted a second time.
“I consider it highly unlikely that the DNA could have ended there in a different way from during the actual killing,” he told NRK.
Astri Aas-Hansen, the lawyer representing Juel Johanessen's parents, said that they hoped that the 38-year-old would confess.
“The family has a very great hope that the arrested person confesses, so they are able to get answers, not only to the question of who killed their daughter, but also to the very many ‘why' questions they've had all these years,” she said.
The application of cutting edge DNA techniques to old murders is nothing new, with US police in 2013 laying the notorious “Boston Strangler” case to rest once and for all by DNA testing the corpse of Albert DeSalvo, a convicted rapist who was long the chief suspect, and matching it to DNA in seminal fluid found on Mary Sullivan, one of the strangler's 11 victims.
DeSalvo admitted to all eleven of the strangler cases, but then recanted, leaving doubt over whether he really was the strangler. The match, to at least one of the victims, indicated that he was.