Da Costa, a sex worker in Stockholm in early 1984,^[1][2][3] disappeared during Pentecost on 10 June, or soon thereafter.^[3] On 18 July, parts of her dismembered body were discovered under a highway overpass in Solna, just outside Stockholm; additional body parts were discovered elsewhere on 7 August.^[2][4] Da Costa's body was identified by her fingerprints.^[3] Her head, internal organs, one breast and genitalia have never been found,^[3][2] and no cause of death could be determined.^[2]

Shortly thereafter,^[2] Teet Härm, a forensic pathologist in a laboratory at Karolinska Institutet, was suspected of the crime.^[1] He was known to have met sex workers in the past, and his workplace was located between the two places where the victim's body was found.^[2] He was arrested and released.^[1]

At this time, the wife of Thomas Allgén,^[2] a general practitioner, alerted the police that their 17-month-old daughter might be an incest victim.^[5] Pediatric examinations found no evidence of abuse,^[5] and the doctor and his wife separated in late 1984.^[1] Later in 1985, the wife told police that her 27 month old daughter had begun talking about witnessing a dismemberment.^[5][6] Since the pathologist and the general practitioner knew each other superficially, the police connected the cases.^[7] The following trials also contained testimonies from the 2½-year-old child's stories, interpreted by her mother and evaluated by a child psychologist and child psychiatrist.^[2]

In 1986, police resources were stretched thin after the murder of Swedish Prime Minister Olof Palme, so the dismemberment case was shelved until the following year. Härm and Allgén were arrested in late 1987 and brought to trial in January 1988.^[8]

The first trial ended in a mistrial after the lay judges were interviewed for the newspaper Aftonbladet on 9 March 1988 and commented on the court's justification for its judicial decision.^[9] In a second trial, the lower court asked the Swedish National Board of Health and Welfare to investigate the circumstances of the case^[1] and found that da Costa's cause of death was unknown. As a result, the two defendants were acquitted, since it could not be established that da Costa died under suspicious circumstances. Although in its verdict the court found that the defendants had in fact dismembered the victim's body,^[9] the statute of limitations for that crime had expired.^[10]

On 23 May 1989, the Swedish authority for medical-negligence assessment rescinded the doctors' right to work, and its ruling was upheld in a 1991 appeal.^[1] The doctors have appealed to several courts, including the Supreme Court of Sweden, the Supreme Administrative Court of Sweden (Regeringsrätten) and the European Court of Human Rights, none of which has overturned the ruling.^[11]

The case has been the focus of several books, investigative articles and television documentaries. Author Hanna Olsson published the book Cathrine och rättvisan (Cathrine and the Justice) in 1990, highlighting the patriarchal nature of the justice system and how women in prostitution were not seen as reliable witnesses. Journalist Per Lindeberg published Döden är en man (Death is a Man) in 1999, questioning the police investigation and contending that the men were victims of a miscarriage of justice caused partially by extensive media coverage. In 2003 journalist Lars Borgnäs published Sanningen är en sällsynt gäst (Truth is a Rare Guest), opposing Lindeberg's position and theorizing that da Costa was murdered by a serial killer.^[12]

In 2006, the doctors demanded 40 million kronor (about US$4.8 million) in damages for loss of income during the years they could not practice and for defamation.^[13][14] Their demand was refused when the Chancellor of Justice, who handles questions of voluntary damages, ruled that such a large claim should be handled by the courts.^[15]

On 3 April 2007, the two men's attorney registered their claim for 35 million kronor in damages at the Attunda lower court.^[16] On 30 November 2009, the trial of the Swedish state began, ending shortly before Christmas.^[17][18] In an 18 February 2010 judgement, the court ruled that the doctors were not entitled to damages.^[18][19]

Da Costa's murder has inspired multiple works of fiction, such as Stieg Larsson's internationally successful crime novel The Girl with the Dragon Tattoo^[2] and works by Katarina Frostenson^[20] and Sara Stridsberg.^[21] The statute of limitations for the killing expired in 2009 and prosecutors suspended their investigations on 1 July that year.^[4]

• List of solved missing person cases
• List of unsolved murders

• Borgnäs, Lars (2003). Sanningen är en sällsynt gäst: sökandet efter Catrine da Costas mördare (in Swedish). Norstedt. ISBN 9789113011769.
• Lindeberg, Per (1999). Döden är en man (in Swedish). Fischer & Company. ISBN 9789170548888.
• Olsson, Hanna (2005). Catrine och rättvisan (in Swedish). Stockholm: Pocky. ISBN 9789185011209. OCLC 666273396.
• Rajs, Jovan; Hjertén, Kristina (2001). Ombud för de tystade (in Swedish). Norstedts. ISBN 9789113009094.

• Sjöberg, Lennart (9 November 2003). "A Case Of Alleged Cutting-Up Murder In Sweden: Legal Consequences Of Public Outrage". The Journal of Credibility Assessment and Witness Psychology. 4 (1). Department of Psychology of Boise State University: 37–62. ISSN 1088-0755. Archived from the original on 24 August 2007. Retrieved 4 April 2007.
• Per Lindeberg's web site Mediemordet.com