Stig Millehaugen, 53, has now been at large for over three days.
The police have received thousands of tips, but nothing has led to any results.
According to Johnny Brenna, a former police officer who previously hunted Millehaugen, the double killer may have changed his appearance.
He is said to have done so after previous escapes, according to information to Dagbladet.
The last traces of the double murderer Stig Millehaugen, 53, were at Oslo Central Station on Wednesday.
A surveillance camera filmed him with a large backpack and his phone is said to have connected to a mast in the Oslo area.
After that, it has been completely quiet and Millehaugen has disappeared without a trace.
No breakthroughs
Several Norwegian media report that the police have received thousands of tips in the case, but none of them have been decisive or had information that led to any breakthroughs in the hunt.
The Norwegian newspaper VG has interviewed former police detective Johnny Brenna.
Brenna has experience of hunting Millehaugen. He took part in an operation in 2001 that led to the arrest of Stig Millehaugen in a garage in Oslo.
That time, the double killer had been on the run from prison for eight months.
“Needle in a haystack”
The former scout calls the next day critical. If you do not find Millehaugen then it can take a long time before an arrest can be carried out.
– My experience is that if there is no arrest for the first two or three days, it can take a long time before he is found. It then becomes like a needle in a haystack, he says.
Brenna tells Dagbladet that Millehaugen may have changed its appearance.
– He can look like another person. Not much is needed. Beard, wig, jogging clothes. things that make you no longer see that he is. During previous escapes, he has changed his appearance, says the former police officer.
It is not excluded that Millehaugen may have fled to Sweden. Swedish police have also been involved in the case. Among other things, an attack was made on a villa in western Sweden last Friday.
However, the double killer was not there.
Two murders
In 2012, Stig Millehaugen was sentenced to 21 years in prison for murder, the Norwegian law’s most severe punishment. He was convicted of murdering gang leader Mohammad “Jeddi” Javed.
Millehaugen is also convicted of having shot dead the prison guard Jon Arild Martinsen in connection with an earlier escape. For that murder, the penalty was 17 years.
He has been described as “Norway’s most dangerous man”
According to the police, you should not approach Millehaugen if you see him, but instead sound the alarm.
– We urge the public to contact the police if you see him. And that you do not do anything on your own, said Anne Haave, prosecutor in Trøndelag police district on Wednesday.