The keys were not 100% planted and, if they were, how did Avery's DNA get on them? I guess they planted his DNA on the keys but forgot to do the same in the bedroom and the garage. Again, those are questions that can't be answered by the conspiracy theorists.
In addition, the police run the license plate or request the license plate of a missing person? I don't find that odd. I'd check to see if the tag was recently run by another department or get the exact make and model of the vehicle since that's what you're looking for first prior to seeing the actual license plate. Or am I supposed to believe that police had the vehicle in their possession and ran the license plate to let the world know they had the vehicle in their possession? It makes no sense.
And if the police planted the bullet as well, how did the victim's DNA get on the bullet? Maybe the police killed her to frame Avery? And where did the police get the bullet if Avery's gun was in his bedroom?
They had access to both of their DNA.
DNA is everywhere on everything you interact with. If you're in someone's trailer...rub the key on the floor would probably do it.
Also, they were given something as a sample of teresa's dna for matching purposes...gotta have something to match against. Typically they ask for a hairbrush.
Thats basically a DNA magic wand at that point. Wave it across an old bullet found that was shot years ago and VOILA! its got her dna on it.
I actually dont think police had anything to do with killing her. I think someone else definitely killed her. Brandon and Scott would be my best educated guess.
The police just saw it as a huge opportunity to avenge themselves of a lawsuit they were fixing to lose against Steven.