Mrsic was born in the Rasavci village near Prijedor, SR Bosnia and Herzegovina, Yugoslavia, to father Momir and mother Radojka.

Dragomir moved with his mother and two older siblings to Sweden aged a month and a half, and was brought up in Fittja, a suburb of southern Stockholm.

His father worked as a chef at Grand Hôtel in the city, his mother as a cleaner at the local school.

His two siblings, sister Ranka and brother Radomir "Rajko", died due to drug usage.

In 1990, he and his friend Liam Norberg were involved in the robbery of bank Götabanken; he stood guard some hundred meters away.