Professor Jasper Tempest, a genius Cambridge University criminologist with OCD and an overbearing mother, advises the police. British version of the Belgian crime drama of the same name.
Series 3, episode 4 is about murder by poisoning and v happens at the beginning. You can avoid it but visual images of murdered people are shown too throughout which may be triggering for people. All other episodes in series 1 to 3 are safe.
The professor's new pet fish is found dead by the housekeeper. She replaces it with another ( without telling the prof) & ithe new fish tells the professor his name is Walter. Evidently the Professor overfed the 1st one. :-(
Occasional flashback scenes, worst one is in S1E6. It's strongly implied that the main character's father was highly abusive before his death before the events of the first episode.