The new testing technique arose out of a study in which researchers were examining the genes responsible for human albinism. As part of the research, scientists studied a large population in order to learn whether the genetic variations they had identified as potentially contributing to albinism occurred with the same frequency among people with normal pigmentation. Researchers learned that individuals have different variations, and these variations are not always associated with albinism; however, these variations changed the protein encoded by the gene in specific ways. Researchers compiled a list of all known changes in these genes and began evaluating them. The research was based on an examination of the DNA blueprints of 800 university students. The tests gave researchers four objective measures of pigmentation to compare with their DNA blueprints analyses. Scientists then used a statistical model developed by Robert Valenzuela, a fourth-year genetics graduate student, in order to determine the three best SNPs (Single Nucleotide Polymorphisms) to explain each pigmentation variation. The resulting analyses enabled forensic scientists to determine hair, eye, and skin color through the testing of a DNA sample. With DNA blueprinting, analysts determined a person's hair color with 70-percent certainty; the ratio of brown-black to yellow-red in a person's hair with 43-percent certainty; skin color variations with 50-percent certainty; and eye color with 76-percent certainty. This article discusses the potential uses of this DNA analysis in criminal investigations as well as its limitations and challenges, such as current DNA backlog concerns and a suspect's alteration of his/her visible features.