How is metal identified and compared in CSI?
The first thing that you're going to do is you're going to look for the major constituents of the metal. Is it copper? Is it lead? We use a variety of analytical techniques that are available to us. Spectral photometric techniques, X-ray technology techniques are quite prevalent in, or pretty much available, to crime labs for looking at the major constituents of metals. When it comes to looking for the trace elements that are present in metals, the thing that gives metal its fingerprint, "fingerprint characteristic" requires sensitive technology. The crime labs must call upon equipment that has a high degree of sensitivity that can seek out and identify trace elements and trace metals that are present at concentrations of a percent or less. They serve as a fingerprint for comparing one metal against another.