The SLMPD would like residents to know about the use of vehicle scanning tools in the St. Louis metro area. The below depicted computers and frequency scanning devices are conduits for possible vehicle theft. These scanners can reach 20-25 yards and penetrate the walls of your home. If you see someone outside your home or in your alley using a device larger and 4-5x thicker than a phone, please report the activity to 911.
RFID blocking, anti-theft devices (example here, via Amazon) can help block signal scanning. Additionally, law enforcement recommends not keeping your keys close to entryways (keeping keys in the middle of your home creates more space between the scanning device and your fob).