Ensio Kalevi Koivunen (23 June 1930 – 27 May 2003) was a Finnish serial killer who poisoned three female hitchhikers using carbon monoxide in the summer of 1971, and thereby got the nickname Häkä-Enska ("Carbon monoxide-Enska").
Ensio Kalevi Koivunen (23 June 1930 – 27 May 2003) was a Finnish serial killer who poisoned three female hitchhikers using carbon monoxide in the summer of 1971, and thereby got the nickname Häkä-Enska ("Carbon monoxide-Enska"). (en)
Ensio Kalevi Koivunen (23 June 1930 – 27 May 2003) was a Finnish serial killer who poisoned three female hitchhikers using carbon monoxide in the summer of 1971, and thereby got the nickname Häkä-Enska ("Carbon monoxide-Enska"). (en)