Firearm and tool mark identification relies on criteria that have been accepted in the field to assist firearm examiners in determining if a bullet has been fired from a particular firearm. In this research, criteria for firearm conclusions were reviewed, in light of current challenges by the scientific and legal community concerning the reliability of firearm and tool mark identification theories and practice. The aim of the research is to determine the effectiveness of Consecutive Matching Striae (CMS) criteria with respect to two-dimensional and three-dimensional marks viewed on both known and unknown test bullets from different caliber weapons. This particular research was conducted using .25 Auto, .380 Auto, 38 SPL, 9mm, .40 S&W, .45 Auto, and 7.62x39mm bullets. All data were used to evaluate the validity of CMS for identification purposes by examining groove impressions. The results revealed that current CMS criteria were valid for firearm identification but some known match comparisons were excluded when applying CMS criteria. Therefore, new criteria were proposed for assistance of firearm identification.--Abstract.