Soisalon-Soininen was assassinated in 1905 when a young student called Lennart Hohenthal murdered him at his apartment in Helsinki.
[1] Johnsson was born in Pielisjärvi, and graduated from the Kuopion lyseon lukio (in Kuopio) on 5 June 1875.
In the morning at 10.30 AM a young man of a heavy build (Hohenthal) dressed as a Russian officer came to Soisalon-Soininen's apartment in Helsinki.
Having deceived the police posted outside, Hohenthal rang the doorbell and a valet, in fact a disguised policeman, opened the door.
Juhani) who was the son of Soisalon-Soininen came to the room and joined the policeman in firing upon the assassin.