Juhani Aataminpoika was a farmhand from Vesivehmaa in southern Finland. In the autumn of 1849, over about five weeks, twelve people died in the countryside of Häme around Heinola, among them his own mother. He was sentenced to death, and the sentence was changed to life imprisonment by Emperor Nicholas I. He died in custody at the Viapori fortress, now known as Suomenlinna, in 1854. His name is written Aataminpoika or Adaminpoika in Finnish; in Swedish he is Johan Adamsson.
He was born on July 31, 1826, in Vesivehmaa, then part of the Grand Duchy of Finland under the Russian emperor. In 1847 he was caught for the theft of a horse and sentenced to about a year of forced labor at the Hämeenlinna fortress. His family background, schooling and other early years are not on record.
The deaths fell in October and November 1849: twelve of them, over about five weeks, in Häme and elsewhere in southern Finland. The dead included his mother and other members of her household, among them a sister. The rest were people living in the surrounding district. Their names are not on record, and neither is the order of the deaths.
In October 1849 he returned to the Heinola area, before the series of deaths had ended. In November 1849 he was taken into custody in the village of Vesijako.
The proceedings were long and drew wide public attention. The court that tried him and the date of its verdict are not on record. He was sentenced to death ("tuomittiin kuolemaan").
The death sentence was not carried out. Emperor Nicholas I pardoned him, and the sentence became life imprisonment, because Finnish law no longer carried out death sentences in practice. The punishment was a life sentence together with corporal punishment. Which authority carried out each step between the court and the Emperor is not on record.
In January 1853 he was moved to the Viapori fortress, the sea fortress at Helsinki known in Swedish as Sveaborg and today as Suomenlinna. Placing him there was unusual. The writer and journalist Zacharias Topelius saw him at the fortress.
He died at Suomenlinna in 1854, after about a year and a half in custody. The month is given as August and also as September 1854. The cause of death is not on record.
The historian Teemu Keskisarja wrote a book about him, Suomen ainoa sarjamurhaaja (Finland's only serial killer). A Finnish musician has recorded a ballad about the case.
The number of killings covered by the court's verdict is not on record, so the figure of twelve rests on attribution. The court, the date of the verdict and the legal charges are not on record. The month of death differs between August and September 1854.
July 31, 1826: born in Vesivehmaa.
1847: sentenced to forced labor for horse theft.
October to November 1849: twelve people die in Häme and around Heinola.
November 1849: taken into custody in Vesijako.
Date not on record: sentenced to death; the sentence is commuted by Emperor Nicholas I to life imprisonment with corporal punishment.
January 1853: moved to the Viapori fortress.
August or September 1854: dies in custody at Viapori.