Chapter 1 - Scope of application of the criminal law of Finland
Section 6 - Offence committed by a Finn
(1) Finnish law applies to an offence committed outside of Finland by a Finnish citizen. If the offence was committed in territory not belonging to any State, a precondition for the imposition of punishment is that, under Finnish law, the act is punishable by imprisonment for more than six months.
(2) A person who was a Finnish citizen at the time of the offence or is a Finnish citizen at the beginning of the court proceedings is deemed to be a Finnish citizen.
(3) The following are deemed equivalent to a Finnish citizen :
(1) a person who was permanently resident in Finland at the time of the offence or is permanently resident in Finland at the beginning of the court proceedings, and
(2) a person who was apprehended in Finland and who at the beginning of the court proceedings is a citizen of Denmark, Iceland, Norway or Sweden or at that time is permanently resident in one of those countries.
Residence Jurisdiction
Nationality jurisdiction - national proceedings
EDIT.