Shelling out evidence: NIST ballistic standard helps tie guns to criminals

(Phys.org) -- Thanks to a new reference standard developed by the National Institute of Standards and Technology (NIST), law enforcement agencies will have an easier time linking the nearly 200,000 cartridge cases recovered annually at U.S. crime scenes to specific firearms. http://phys.org/news/2012-08-shelling-evidence-nist-ballistic-standard.html#nwlt