From Amazon Prime:

Five years ago, a serial killer murdered three young men but was never found. Now, criminal profiler Louise Bergstein is asked by the terminally ill mother of a victim to help solve the case. Teaming up with the police, Louise discovers a distinct pattern to the killings-and the hunt only intensifies as the murderer strikes again in this Danish thriller. CONTAINS VIOLENCE AND GRAPHIC SCENES.

From Amazon Prime you can stream the 8 episodes of this well-done Danish serial-killer series.  Each episode lasts about 45 minutes. English subtitles.

From the very beginning you know who the killer is: Peter is a father with son Johannes . Peter’s marriage has failed and his wife has moved to Singapore.  Louise and Karina are two of the detectives working to solve the case. Louise is a profiler who, in an original plot twist , completely fails to recognize as killer the handsome man whom she meets quite by accident, after which the plot thickens a bit.

Poor Johannes is baffled by the strange behavior of his father. Johannes sorely misses his mother but is prevented by his father Peter from seeing her.

Because Peter kidnaps and tortures his victims,  the crime photographs can be quite gory.  But because the series is done so well, if you can get past the ugliness, DO NOT MISS!