For more than a decade, there has been an academic debate over the deterrence effect of concealed carry weapon (shall issue) laws. However, all previous studies do not consider the types of gun-carry laws in place prior to the adoption of “shall issue” laws. Using difference-in-difference methodology, findings of this study imply that considering the type of regulations that states had prior to passing “shall issue” laws matters and “shall issue” laws do have a deterrence effect under certain circumstances. Adopting “shall issue” laws only reduces the crime rate in states with “no issue” laws in place, and “shall issue” laws are redundant to “may issue” (restricted concealed carry) laws in terms of crime reduction.