What is a 'standard reference sample' in CSI?

What is a 'standard reference sample' in CSI?

I spoke earlier about what a crime lab does in terms of examining physical evidence. And one of the things it does is to compare physical evidence. To compare physical evidence for the purpose of ultimately determining whether two or more objects have a common origin. So for example, if you have a hair at a crime scene, you have to have something to compare it against. Normally, hopefully, it will be hair taken from the suspects head. But it could be hair also that came from the victim. So a thorough collection of physical evidence at the crime scene must not only relate to what is present at the scene in terms of commission of the crime, but it must also relate to taking things from individuals that ultimately could be used for comparison purposes. Things such as fingerprints, hair, and samples of, biological samples, that allow for us to determine that persons DNA. This is ultimately carried out for the purpose of conducting the comparison.