Constitutional theories refer to the teories which explain criminality by reference to offenders' body types, inheritance, genetics, and/or external observable physical characteristics.
Other definition:
Constitutional theories refer to theories such as Lombroso's or Sheldon's that locate the origins of criminality in a person's biological or psychological make-up. It refers tp to one's physical constitution, not a legal constitution.
Other /More definition:
Constitutional theories are those which explain criminality by reference to offenders" body types, inheritance, genetics, and/or external observable physical characteristics.