A short list of things that should not matter:
-Steven Avery is a shit person.
-Steven Avery has a short temper.
-Steven Avery didn't get along with some people.
-If he hadn't been in prison for 18 years for someone else's crime, Steven Avery might have done this or that.
I'm appalled and how often, here and elsewhere, I've heard related statements used as lazy justification. Want to know how/why people fabricate evidence in court cases? Can't believe it? Here it is. You see it in these arguments. We are very good at deciding certain people should probably go away just in case.
The Avery family is a lot of things, including a prime example of how people with issues beget more people with issues. SA couldn't stay out of jail but was father or stepfather to what, five kids before 23? How many if he hadn't been in prison? Who could say. Tons of people in that family just ripe for petty crimes or worse, as well as systemic victimhood. I grew up like this, even lived in a salvage yard for a while. My father was very like Avery, only with more basic cleverness, I think. It makes me hate him a little on a personal level. But none of that should matter. ALL that should matter is that there are enormous gaping holes in the state's case against these two individuals, there's no explanation for what happened to Halbach, and a grave miscarriage of justice occurred during these trials. We don't convict for stupid or mean or potential. At least, we shouldn't.