Or, you know, the criminal committing the crime without a phone, and OP walking past the wrong place and the wrong time. A lazy police officer making a geofenced information request to Google and getting only one result...
as I plotted the perfect murder I noticed that extr often walked past my victim's house at 9 at night on a relaxing evening stroll listening to music on their iphone. I decided to give the police a lead to good too pass up!
on edit: had edited seconds after post to change to to too, and mixed up the order of to and too, this edit fixes that mixup.
Its a shame Agatha Christie isn't still alive today. No doubt, she'd have thought up some marvelous plots involving smartphones and I dare say the internet and cyber crime. :-)