My thoughts on season 2
Zellner destroyed all the forensic evidence brought by the prosecution. She also pointed towards other suspect that were never investigated. All the questions I had after season 1 were answered by her.
Too many clips recycled from the first season. Also, the documentary lingered too long around Avery's aging parents wobbling around.
The Wisconsin Justice Department and police forces are rotten to the core and it appears little can be done about it. They know their case against Avery and Dassey is utter BS, but they would rather keep reinforcing a tower of lies than admit they ever did a single mistake.