They believe she may have seen the killer shortly before he stabbed 8 year old Mohammad Ammouri, who was on his way to school, and 56 year old Anna-Lena Svenson, who was only 25 metres from her apartment block and on her way to her job in central Linköping. The boy died at the scene and Mrs Svenson died from her wounds in hospital some hours later.
The murderer escaped but police found his blood-stained clothes hidden near the scene of the murder and concluded that the killer had seriously injured his own right hand in the attacks. DNA samples were taken from the clothes as well as from the so-called butterfly knife which was found shortly after the murders.
Soon after the attack, police received an anonymous letter which included a description of the man they believe is the murderer:
“I met a man. He had a dark, probably black jacket and a dark hat. He was about 180 centimetres tall and between 20 and 25 years old. He looked like a Swedish youth.”
Police believe the woman later made a “short and stressed” call to officers working on the case.
But despite the abundance of evidence police have not yet made an arrest. They have accumulated over 12,000 documents and held 2,000 interviews but are now particularly keen to speak to the anonymous woman.
“The information she has given us so far is interesting enough for us to want her to get in touch immediately,” said Jan Staaf, a member of the investigation team.
“From earlier witness information we know that the attacker looks almost identical to the man she met.”
But while police believe the woman has important information, Staaf told Dagens Nyheter that that did not mean they were close to making an arrest.
“We don’t have any particular suspects in the case, but we have gathered an awful lot of evidence and we hope that the suspected attacker is in there somewhere,” he said.
Expressen reported that on Monday police interviewed ten people, both in Linköping and Stockholm. All of those interviewed agreed to give a sample of their DNA, said the paper, which also noted that a 22 year old psychologically ill man with a record of breaking knife laws and violence was of “high interest”.
“I can’t say anything about that,” said police inspector Nils Ahlberg. “But I can confirm that I am going to Stockholm to hold interviews with a number of people, among them a woman. All are equally interesting for us.”
The father of the murdered boy told Expressen that he hopes the police are close to a breakthrough.
“We have lost our child and the murderer has lost himself,” said Hassan Ammouri.
“Sooner or later he’ll be arrested and punished with life imprisonment. We’re not going to get our son back but an arrest could put an end to our suffering.”