As made clear in previous chapters, the goal when carrying out crime linkage analysis is to identify patterns of offending behavior that meet two criteria: behavioral similarity and behavioral distinctiveness. Behavioral similarity exists when offenders behave in the same or similar way across crimes they have committed. Behavioral distinctiveness exists when the behaviors exhibited by different serial offenders differ from one another. When offenders behave in a relatively similar and distinct fashion, it should be possible to link offenders to the crimes they have committed and to differentiate between crimes committed by different offenders with some degree of accuracy. To accomplish this, a threshold must usually be set to determine when crimes are similar enough to warrant a linkage decision being made.