My question involves police conduct in the State of: Minnesota

I need direction regarding next steps, Civil suits, Civil attorneys and more...

BACKGROUND
I was involved in a case where my ex wife attacked me, I defended myself, retreated, and she stabbed me in the back with a butcher knife. I was charged with Assault 2 (among other things), and acknowledged the fact that I defended myself and hurt my ex wife, and was found guilty. It was obvious that she should have been charged with attempted murder, the Jury approached the Judge questioning why my ex wife wasn't charged, etc...

ISSUES
The following happened (and I have documented proof of all of this):

- The Police ALLOWED EVIDENCE TO BE DESTROYED, including but not limited to:
* Allowed my ex wife to wash her hands (and my blood and the evidence off her hands) when they arrived at the scene.
* Allowed my ex wife to take her car and get a carwash (her car had my blood on it, which was evidence).
* Directed my ex wife NOT to enter the crime scene, yet she did and admitted that she had taken a mop to clean up some of the blood in the garage (where she stabbed me). The police did NOTHING, apparently it was okay to alter a crime scene??
* Witnesses outside the courtroom saw and heard the Prosecuting Attorney speaking to the Police and directing them as to how to answer questions MINUTES BEFORE THEY WERE ON THE STAND.

...the list goes on and on, and grows from 'a single incident/accident', to 'multiple incidents/incompetence' to 'apparent misconduct and more...'

I would appreciate ANY and ALL input...this has RUINED my life and the life of my FAMILY...

Thank you in advance