geesh, I'm not sure where you should start lol
I will give you a few suggestions and some great links
First, bookmark this site:
http://www.stevenaverycase.org/ shortly after MaM aired, there was a crowdfunding effort to obtain all the transcripts, exhibits, some photo's (they were stupid expensive), they are all on this site.
From that site, you can start by reading the transcript of the trial. Here is a day-to-day index, gives a quick overview of who is testifying and links you directly to their testimony
http://www.stevenaverycase.org/jury-trial-index/
Under Miscellaneous records, you will find the CASO (Calumet County Sheriff's Dept. report, it's over 1000 pages!!)
http://www.stevenaverycase.org/wp-content/uploads/2016/04/CASO-Investigative-Report.pdf
you will also find MTSO's report (Manitowoc County Sheriff's Dept report, much shorter )
http://www.stevenaverycase.org/wp-c...-Summary-Report-on-Homicide-Investigation.pdf
If you would like to see what was filed in Avery's Civil Suit against MTSO:
http://www.stevenaverycase.org/civilsuitdocuments/
I hope this helps ILoveDateline
If you have any questions or are looking for something and can't find it, let me know, I will see if I can find a link for you

There is a boatload of info out there now that wasn't available a year ago, I remember waiting impatiently for these documents LOL
Oh and... if you would like to read Brendan's trial transcripts, they are stickied at the top of forum here

I believe in that thread, there is also links to all of his interrogations, or the one's that they recorded ;-)