Three disappearances in one summer
On 11 July 1971, 23-year-old Salme Metsänikula was travelling back toward Turku after visiting family. Yle's historical archive records that she reached Koria before disappearing. Her body was found weeks later in a wooded area in Inkoo.
On 14 August, 17-year-olds Pirjo Laiho and Ritva Raijas set out from Helsinki toward Hyvinkää by hitchhiking. They never reached their destination. Their belongings were later found near the old road by Seutula airport, and the two girls were found dead near Ridasjärvi.
A linked investigation
Police connected the cases as evidence accumulated across southern Finland. Yle describes the combined inquiry as the largest and most complicated homicide investigation Finland had seen in roughly a decade. Public tips, vehicle observations and physical evidence helped investigators narrow their attention to Ensio Koivunen, a man with an extensive record of property offenses.
Koivunen was arrested in September 1971. The investigation examined his car, his movements and property connected with the victims. The case drew intense public attention because of the number of victims, the geographic spread of the evidence and the uncertainty surrounding how each woman had died.
Trial and appeals
Koivunen was convicted in proceedings arising from all three deaths. The legal history is important because the eventual appellate outcome differed from the shorthand often used in later true-crime accounts. A later Finnish retrospective notes that higher courts reduced the homicide classifications from the initial murder or manslaughter findings, while maintaining a very severe aggregate sentence for offenses connected to the three women.
Historical accounts report a final 25-year custodial term under the penal terminology then in use. Because Finnish sentencing law and terminology changed after the 1970s, this page avoids translating the historical sanction into a modern equivalent.
Why the case endured
The case became a reference point in Finnish crime reporting. Yle's archive emphasizes both the scale of the police work and the role of public information in identifying the suspect. Later books and documentaries have revisited the investigation, the appeals and the gap between the popular “hitchhiker murders” label and the precise legal findings.