You wouldn't know they had no history of leaving their local area unless you interviewed them.

Why does not the investigator have to supply some sort of evidence that she has a history of leaving their local area rather than putting the onus on the accused? This line of argument is halfway to "guilty until proven otherwise".

You and the GP that replied to me are way overstating what it means to be a "suspect". It just means the police are investigating you and consider it a possibility you've committed the crime. On its own, is not a sufficient status to search your home, subpoena your ISP, or arrest you - all of those things require a much higher burden of evidence, and oftena third party (judge's) approval. People routinely become "suspects" on much flimsier evidence than an unreliable software match - if I call in an anonymous tip that I saw you acting suspicious near the crime scene, you will probably become a suspect.

If you'd like, you can replace the term "suspect" in my post with "person of interest", which colloquially implies a lot less suspicion but isn't practically any different in terms of how the police interacts with you.