Murder of Helén Nilsson

On the evening of 20 March 1989, ten-year-old Helén Nilsson was abducted in Hörby, Sweden. She had planned to meet two friends outside a grocery store at 19:00, and after not finding them, took a short walk around the block. She encountered friends of her sister, who told her two girls were waiting outside the store. Seeing the girls leaving the parking lot, Nilsson ran after them — the last confirmed sighting of her. When she failed to return home shortly after 20:00, her family grew worried, and a search began. Police were notified at 22:10, and the disappearance quickly drew significant media attention. Five independent witnesses reported seeing a young man, aged 20–25, in the area at the time Nilsson vanished; one witness saw him force a girl into a car, though this witness later confirmed the man did not resemble the person eventually convicted. Nilsson was found murdered six days later in woods approximately 20 kilometres outside Hörby. Police determined she had remained alive for a couple of days following her abduction.

Multiple arrests occurred during the investigation without resulting in charges. Two days after the abduction, a man living in the same area was interrogated and had his home searched but was never named a suspect. In 2002, the case was reopened, prompting a full review of interrogation transcripts and other records. This led investigators to two cousins, one of whom had a history of attempted rapes in the 1980s; several women who had been ten years old in the area during that decade came forward describing harassment or assault by this man. The two cousins had given conflicting accounts of their whereabouts on the day of the abduction and had been seen behaving unusually near the grocery store. They were detained in 2002 but released after prosecutors found insufficient grounds to hold them.

A small sperm sample recovered from Nilsson's body in 1989 was preserved but could not be analyzed with the technology of the time. In 2002, it was sent to the Forensic Science Service in Birmingham, UK, yielding a DNA profile by August 2003. In April 2004, police selected a group of 29 men connected to the investigation for interrogation and voluntary DNA sampling, prioritizing those living closest to the crime scene. Confessed (and later discredited) serial killer Thomas Quick (Sture Bergwall), long rumored to be connected to the case, voluntarily provided a sample to be ruled out, though police had not considered him a suspect. A match was confirmed on 23 June 2004, leading to the arrest of Ulf Olsson that same evening.

Olsson, dubbed "the Helén man" (Helénmannen) in Swedish media, was found guilty in December 2004. In April 2005 he was sentenced to life imprisonment despite being found mentally ill; on appeal, a higher court determined his condition warranted psychiatric care instead. The case was later dramatized in the 2020 SVT series "The Hunt for a Killer" (Jakten på en mördare), with actor Magnus Schmitz portraying Olsson.