TLDR Ryan Hillegas
Ryan Hillegas didn’t “guess” Teresa Halbach’s password and username as he claims on the stand in court. I’m pretty sure he knew it all along. Keep in mind that Ryan had been Teresa’s boyfriend for FIVE years. This means that he was well aware of where Teresa would be and when. And he had had access to this information over long periods of time. As Teresa returned again and again to Avery Auto Salvage, to take pictures of vehicles that Steve and possibly some of the other Avery’s wanted to have posted in Auto Trader, Hillegas had PLENTY of time to meticulously plan. Ask yourself whether your belief that either Steven or the Manitowoc sheriff’s were responsible would be challenged if you happened to know that a disgruntled ex-boyfriend had been stalking Teresa ongoing, and just so happened to have direct access to all of her personal information.
And it’s not just that this information would have allowed Hillegas to know exactly where and when Halbach would be somewhere, it would have very possibly been the worst sort of information that a scorned lover should see: intimate details of her romantic life with other men revealed in emails (we MUST assume he also had access to her email), comments highly critical of Ryan and who knows what all else. The imagination reals. Before poor Teresa Halbach was murdered someone was burning with rage, and I believe that someone was very likely her ex, Ryan Hillegas.
But what about Steven Avery’s blood in Teresa’s RAV4? Ryan was working as a nursing or finishing up his nursing clinicals as a student. He could VERY easily have had access to Avery’s blood. Any nurse who works in a hospital (and I once held that job myself so I know!) has access to patient medical records. And not just that. They also have access to blood and body tissue. Hillegas likely had unusual resources that most people planning a murder don’t. Could he have entered something into the system to order a new test for some reason? You know, it’s not as far fetched as you might think that Ryan Hillegas might have even drawn his blood!
As far as the cops planting evidence, it seems much more likely that Hillegas was the one pulling the strings all along. It’s impossible to say at this point how Hillegas might have killed Teresa but once the deed was carried out, all he had to do was surreptitiously burn the body, and then, under the cover of darkness, throw the remains in the burn pit behind Avery’s trailer.
The reason things didn’t go quite as planned is because of Ken Kratz, ironically because it was he who came up with the elaborate story of Teresa being raped, tortured and mutilated. If this nonsense had never been concocted, it would have simply been assumed that the murder took place in the RAV4, and after it was over, her body was burned in the back yard, which is basically close to what happened, except that the killer wasn’t Steven Avery.