Forensic Psychology is a diverse and ever-growing discipline.  Forensic psychologist has consistently been at the forefront of the field of social-legal psychology.  The social-legal psychologist performs a number of essential functions within the common law court system..  One function of the social-legal psychologist is the evaluation of potential witnesses.  By categorizing a particular witness one can predetermine, to an extent, what to expect from that individual in future encounters.  A number of different typologies exist.  The Crime Classification Manual (1992) makes a number of witness type distinctions:

• The Distraught Witness - The distraught witness bears a great deal of emotional distress.  This distress is the direct result of either witnessing the crime or indirectly  from their relationship with the victim.
• The Fraudulent Witness - While not having any first hand knowledge of the crime, the fraudulent witness is an active attention seeker whom comes forward to offer fraudulent evidence.
• The Hostile Witness - This witness is deliberately antagonistic and/or noncompliant.  Such an individual may invent facts in order to purposefully mislead the law.  The hostile witness may react this way for two reasons: (1) their relationship to the offender, or (2) a underlying animosity towards the law.
• The Intimidated Witness - This witness fears retaliation from the offender(s) involved or from the criminal element in general.  As a result, the intimidated witness is quite apprehensive.
• The Inventive Witness - These witnesses typically embellish and create details when being interviewed.  This is likely due to an inability to differentiate between fantasy and reality.  They may also have esteem motives, in that they wish to appear important.
• The Reluctant Witness - Witness responds with reluctance due to a natural restraint that is a reflection of their personality.  This particular witness will be hesitant and reserved.  They will not find it easy to talk freely.  Others may feel that the act they have witnessed is "none of their business".