Beck (1999) : 1x4

Beck and his team are trying to find a serial killer whose victims are spread all over Sweden. An obvious connection is that all the victims are women, and they were all in the same class, and Beck thinks that a scandal back in the past has something to do with the murders. But no one wants to talk about the past and it becomes a struggle to find the perpetrator before the final murder - only one woman is still alive.