Source: Original Source from page $23$ of an article, "A Shot in the Light," by Peter Weiss in a $2003$ issue of Science News:

Source material: During the sniper shootings of $13$ people in the Washington, D$.$C$.,$ area last October, police initially uncovered only a sparse trail of evidence$$often just the bullet itself. As tension mounted over several weeks, newscasts repeatedly reported that examinations of bullet fragments were linking the shootings. That coverage brought the science and technology of bullet identification onto center stage. It also drew attention to a system still under development, in which images of bullets, bullet fragments, and bullet cases collected from crime scenes are matched against a database of previously recorded images.

Quotation: Peter Weiss notes that for Washington, D$.$C$.,$ police hunting the mysterious sniper, "a sparse trail of evidence$$often just the bullet itself" $(23).$

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