>> Leaving a phone at home that is not answering calls or creating traffic during the time of interest is also a lead (if you already have a suspect).

Interesting. My phone uses WiFi for everything by default. I wonder if they'd be able to tell (probably via Google?) If I were to leave it home for a day. On the weekend of course, since daily commute will hit the towers except for an atypical occurrence.

With such capability I feel like it's obvious they don't want to stop certain things.