Ten-year-old Helén Nilsson was the victim in a sadistic murder case (Swedish: Helénmordet) in Hörby, Sweden, in March 1989.
The murderer, Ulf Olsson, the so-called Helén man (Swedish: Helénmannen), was convicted in April 2005, having been found after a DNA test in 2004.
A police officer mentioned that she was involved with the investigation of the murder and this prompted a remark from one of the guests about a former colleague of hers, Ulf Olsson.
In December 2004, Olsson was declared guilty and in April the following year he was sentenced to life, even though he had been found mentally ill.
In the 2020 SVT television series The Hunt for a Killer (Jakten på en mördare) about the murders of Helén Nilsson and Jannica Ekblad, actor Magnus Schmitz played Ulf Olsson.
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 Nilsson was in the area and they had been spotted in their car, signalling with full beams and in other aspects behaving "very strange".
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.
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.