Kinda crazy that it lasted this long:
A Maryland database containing a spent casing to match every gun sold in the state since 2000 has been shut down after failing to solve a single crime.
Effective Oct. 1, the Maryland General Assembly abolished the state’s requirement that manufacturers send a shell fired from each gun they sold in the state in order for state police to photograph and catalog the shells for use in potential future investigations. Over a period of 15 years the database collected more than 300,000 shell casings and created “ballistic fingerprints” for them. The system, based on the National Integrated Ballistic Information Network but expanded to include all guns in Maryland, was designed to compare spent casings from gun sales against those found at crime scenes.