As we see in this case, the (likely) person in this case was actually found from the relatively small number of people who fit this criteria, so police were (likely) right to suspect these people.
The issue is not who the police may or may not suspect. it is about reasonable expectation of privacy. If they had obtained this exact same list of people who were near that bank for that time by a means that did not violate their reasonable expectation of privacy, then the evidence couldn't be challenged on that basis.
I’m fully aware of the privacy concerns here; but that wasn’t the topic I was engaging in.
I’m saying that practically, being within a radius as the bird flies does not make you functionally “within the area” when there’s a huge z axis in a city.
When someone robs the retail of the ground floor of a high rise, there are many people who were right on top of the crime scene measured by lat/lon but were actually 10 minutes away by foot, hundreds of feet away in actual distance, and in no way aware it was even happening.
Imagine in the 1980s if every citizen was compelled to carry a ghetto blaster with 100W amplifier and speakers that relentlessly blared our SSN, phone number, home address and bank accounts.
In biblical times, of course, lepers were legally compelled to identify themselves and warn others with analogous methods.
Now today we all voluntarily carry around radio transceivers that loudly blare unique identifiers, perpetually, omnidirectionally, to anyone and anything that will listen.
Wired connections are so aggressively deprecated that we’re also perpetually exchanging every private conversation, and every secret SMS MFA code, and every DNS lookup, over public airwaves.
It’s not our fault and it’s beyond our control, but if you carry such a ghetto blaster, don’t cry to us about expecting privacy.
Surely one of those thousand can be made to look guilty enough for a prosecution. Solves the problem of looking like you're doing something real well.
The system does not care about prosecuting criminals. It cares about prosecuting people for crimes. While it may prefer to prosecute criminals for their specific crimes that is by no means a hard requirement.
Only if it's known that you were ever there in the first place, and people that typically wouldn't ever be considered, like someone who is quietly visiting in the living room of someone who lives nearby, will fall under scrutiny when police are just getting the data of everyone in a certain radius.
A one hour period and 150 meter radius of a bank surrounded by high-rises and public transit? no.