Complex sentence: A social worker, Stefan Lindberg, whose sister becomes a victim of the "Truth Terrorist", is an early suspect, but events soon lead the detective teams in Sweden and Denmark to conclude that the killer has connections to the police.
Split into simpler sentences: A social worker, Stefan Lindberg, whose sister becomes a victim of the Truth Terrorist, becomes an early suspect. However, events soon lead the Danish and Swedish teams to conclude that the killer has connections to the police.