Helén murder

Not everything is known about the details of her abduction, but some events were determined by the police investigation.

Helén had decided to meet two friends of hers outside a grocery store at 19.00, but failing to find them there she had made a short walk around the block. She met a couple of friends of her sister, who informed her about two girls waiting outside the store. Upon looking in that direction, Helén and the sister's friends could see the girls leaving the parking lot, and Helén ran after them. This is the last known observation of Helén Nilsson. Although the police made major efforts to determine where she had been abducted it could never be determined whether it occurred outside the store or on her way home, if she had decided to return home after her friends had left her. [4]

Shortly after 20:00 (CET), the time when Helén should have returned home, the family was getting worried, since Helén's friends had been at her home to ask for her. A search started, and more and more people became involved in looking for the girl. At 22.10, the police was informed and over the following days, the disappearance attracted a lot of media attention. Five independent witnesses had seen a young man, 20–25 years old, at the same place and time as Helén disappeared. One of them saw him force a little girl into his car. The witness has confirmed that the man did not look like the convicted man.

A number of arrests were made over the years. On 22 March, only two days after the abduction and while the search was still on, a man living in the same area as Helén was interrogated by the police and had his home searched. He could not present an alibi but he was never declared a suspect of the crime.

In 2002, the case was reopened with the intention of reviewing all the interrogation transcripts, letters and other available data. One revisited lead consisted of a man who was reported to have attempted a couple of rapes during the 1980s and who lived in the area. He had been with his cousin during the day of Helén's disappearing and the two men presented very different views on what they had been doing on that day. During the new investigations, a number of girls who had lived in the area and been 10 years old at some point during the eighties were questioned, and six of them mentioned being harassed or assaulted by the man.

It could be established in 1989, that the two men had been at the grocery store at the same time that Helén was in the area and they had been spotted in their car, signalling with full beams and in other aspects behaving "very strange".[5]

Several other observations of the two cousins prompted the investigators to detain the two men in 2002. Eventually, the prosecutor determined that there was no reason to keep them in custody and they were let go.

A small amount of sperm was found on Helén's body and was sent to the forensic laboratory in Linköping. In 1989, however, the techniques used were not advanced enough to be able to get any information out of such small amounts but the sample was frozen. In 2002, during the reopening of the case, the sample was sent to Forensic Science Service in Birmingham, United Kingdom, and in August 2003, the DNA profile was received.[6]

In April 2004, a group of 29 men that had appeared in the investigation was selected. The purpose was to conduct interrogations and to ask the men to voluntarily provide DNA samples. There were no priority differences within the group apart from the strategy of starting with those living closest. It had been rumoured over the years that confessed (but later disproved) serial killer Thomas Quick (Sture Bergwall) was involved in the murder and although the police had no interest in him, he was allowed to leave a sample by his own initiative in order to rule him out. A match was reported on 23 June 2004, and Olsson was arrested the same evening.