How does tracing serial numbers on money help the police catch crooks?

Even if the police could check EVERY bill in EVERY bank, shop, highway tollbooth, etc. how would that tell them who spent the money and where they are now?How does tracing serial numbers on money help the police catch crooks?
I doubt that the serial numbers on Federal Reserve Notes are usually recorded on casual transactions. When you use ';cash'; (as FRN are called) to buy a pack of cigarettes or a case of beer, nobody scans the bills to read the serial numbers. The cashier just puts it into her cash register drawer, where it is mixed up with a lot of other bills.





I have yet to see any cashier scanning the serial number off a $1, $5, $10, $20, $50, or $100 bill. I don't think that there is any customary procedure to link store security videos with such serial numbers. In other words, this may be a law-enforcement bluff aimed at discouraging crime by making it seem as if cash were less private than it still is.





One of the reasons for the push for a cashless society, where all transactions must be carried out by credit card, is to terminate the privacy that is afforded to citizens by using cash to pay for their merchandise, making us all more vulnerable to government and corporate identification and scrutiny.





If nobody scans the bill and tags the serial number with some way to identify you as the one who spent it, then the police have no way (as far as I know) to trace you through the cash you spent. Again, this might be a law-enforcement bluff. They like to portray themselves as omniscient, omnipresent, and all powerful, so that you'll be intimidated and think that you can't get away with doing anything they won't like.





In fact, most crimes still go undetected. A significant percentage of the crimes that are detected go unsolved. And for some of the crimes that the police think they have solved, they got the wrong answer. Not every prison inmate who says he's innocent is lying, and for each innocent person in a prison, there's at least one free criminal who's laughing at the cops and the stumblebum legal system.How does tracing serial numbers on money help the police catch crooks?
crooks is a funny word thehehe.





well they cant locate a criminal with the serial number but they can find where the money has been spent at.


and when they get all the locations they can more or less know ones whereabouts and possibly predict their net move to help get them. The can also ask questions to the people who have accepted the money. Maybe the time and date they were there, what were they wearing etc.
Cameras.