Though the use of blood type in forensic investigations is not enough to prove guilt, it may aid in exonerating a potential suspect. In this activity, students act as lab technicians and assist investigators by examining evidence collected at a crime scene. Students first use a presumptive blood test to determine if a substance on a stained piece of cloth may be blood, and then determine the blood type of a sample collected at the scene. Students then compare their results to those of samples provided from two suspects. Kit contains enough materials for 10 groups. Teacher's Manual and Student Study Guide copymasters are included.