The fact that not everyone was a suspect. In the first 3 seasons everyone had a motive no matter how weak it was. The flashbacks were also important. For example in the first season we saw Carla tell the detective that her and Maria weren’t friends and they barely had any interactions together leading up to her death but then we get a flashback that proved she was lying. Those flashbacks also showed the characters acting suspicious, rehearsing lies to tell the police, sometimes even concealing evidence.

In this season Ari shared the majority of her scenes with her family, Guzman and Samuel. Rebe didn’t have a motive, neither did Samuel or Omar or Cayetana because and they rarely interacted with each other so they are immediately crossed off as suspects. Then it turned IT WASN’T EVEN ANY ONE THEM.