The Hunt for a Killer - Season 1 Episode 4 -

Pelle is back from sick leave and placed in the basement of the police station. He secretly begins to go through the Helen case and the group that can solve the murder reappears, now the hunt begins in earnest. At a Christmas party, Monica is taken aside by a woman who tells about a man she thinks may be the killer. She says she contacted the police as early as 1989.