In 2000, I sent a letter to the editor of the New York Times that provided in part:
Different lots of ammunition could be tagged by adding trace chemicals to the gunpowder. Individuals could buy only ammunition designed for the types of firearms they are registered to own, and the relevant information concerning each purchase would be entered in a central database.
Because gunpowder spoils with the passage of time, there is only a limited supply of ammunition in circulation.
As a result, effective gun registration could be a reality within a few years despite the millions of guns in circulation.
Today, the NYT is reporting:
[I]n California, which already enforces some of the nation’s most restrictive gun laws, there is a movement underway against the unfettered sale of bullets.
I guess it just takes time for good policy ideas to percolate up.
Lanthanide-doped ZnAl2O4 spinel was used as a luminescent marker for gunshot residue (GSR). GSR was visually identified on shooters’ hands, as well as on firearms and the firing range. After the shot, GSR was collected and analyzed by several techniques, including FTIR, Raman and emission spectroscopies and SEM-EDS. It was observed that markers provide an optically and structurally unique signature for GSR, allowing their identification by the tested techniques. SEM-EDS shows that lanthanide ions act as a chemical taggant. FTIR and Raman spectra provided a chemical signature of GSR, as well as emission spectra. Thus, it was possible to unequivocally identify GSR, even when lead-free ammunition was used. By employing different emitting centers, it was also possible to distinguish between two types of ammunition, opening a new perspective for traceability.