Witness / 911 – every other aspect of crime has been done, prosecutor, victim, forensics… The only one left is witness, because it is the hardest. Obviously the witness journey is boring, but it can bookend the show. The witnessing, the questioning, the trial, and the “special witness squad” who look after them, which was real in my kidnapping trial in England.
Mexico – this one is juicy. A (small) crack team returns Americans to the US for crimes committed. They get paid secret money from the government. They have people on the border and people in the immigration department. Why? They also smuggle nice people into the US to be with family. Part thriller involving the most dastardly criminals, part human story and happy ending.
Like all great TV it is episodic and has seasonal story arcs.