Malicious prosecution cases are hard to win, because you have to establish that the prosecution was completely without merit and that the prosecution was motivated solely by malice. That is a high standard to meet, but it is one that the McCloskeys, who are litigating attorneys themselves, should be able to meet. I think a Federal civil rights violation 1983 action might arise depending upon what discovery reveals. The emails and texts of prosecutor Kim Gardner should be a gold mine. Leave not a chunk of meat on her financial bones McCloskeys!
I am not an attorney. However, speaking as standard-issue jury material, the lab shenanigans with the pistol are all the proof I need.