At the beginning of his career, he worked for six years as the police chief at Kälviä, from where he was transferred to the Ministry of Justice in 1973.
In the mid-1980s, Lehtola was appointed chair of the planning committee of the Ministry for Major Accident Investigation.
For the general public, he became known as the head of the Estonian Accident Investigation Board.
His other positions of trust included membership of the City Council of Helsinki.
Lehtola started as a city councilor in 2001 and resigned from the council in 2008 after moving to Karjalohja.