Methodology
Gun thefts were established using stolen gun data obtained from the Chicago Police Department through a Freedom of Information Act request from 2000-2023. That data included firearm type, make, model, and serial numbers. The data was joined with crime incident data, which included location descriptions, block-level address, arrest status and more.
The CBS News Data Team obtained data on thefts where either a car VIN, make or model were listed in the report through a public records request to the Chicago Police Department. Not all car thefts listed a VIN, and in many cases, multiple cars were broken into and listed under a single crime report.
To account for this, the Data Team took the most common locations where a theft occurred and a VIN was listed, then applied those location descriptions to other thefts. Those 18 locations included: STREET, PARKING LOT/GARAGE(NON.RESID.), VEHICLE NON-COMMERCIAL, PARKING LOT / GARAGE (NON RESIDENTIAL), VEHICLE-COMMERCIAL, CTA GARAGE / OTHER PROPERTY, AIRPORT PARKING LOT, VEHICLE - COMMERCIAL, POLICE FACILITY / VEHICLE PARKING LOT, CHA PARKING LOT / GROUNDS, CTA PARKING LOT / GARAGE / OTHER PROPERTY, VEHICLE - DELIVERY TRUCK, TAXICAB, ALLEY, RESIDENCE-GARAGE, POLICE FACILITY/VEH PARKING LOT, DRIVEWAY - RESIDENTIAL, RESIDENTIAL YARD (FRONT/BACK).
The location matches resulted in 19,489 likely thefts from cars in 2023.
Cars whose windows were damaged, but no property was reported stolen were classified as damage to a motor vehicle. We removed cases that were classified as domestic, and the results were 15,523 incidents last year.
Those results were then combined with likely car thefts, to arrive at 35,012 likely car break-ins in 2023.
The break-in results were then combined with gun theft data on RD Number to determine what locations netted the most gun thefts from car break-ins.
To establish what crimes were used with stolen guns, data obtained from the Chicago Police Department showed guns inventoried during an arrest. The data included firearm make, model and serial number. That data was joined on serial number to stolen gun data to trace the incidents of stolen weapons to those used on subsequent crimes.