The National Institute of Justice in the U.S. categorizes witness intimidation into overt intimidation and implicit intimidation. Overt Intimidation occurs when someone does something explicitly to intimidate a witness. Whereas, implicit intimidation involves a situation in which there is a real but unexpressed or indirectly expressed threat of harm to anyone who may testify. This is type of intimidation is generally created by the offender’s history of violent retaliation against cooperating witnesses.
Intimidated witnesses can be divided into three categories according to the degree of intimidation experienced:
- A small inner core of individuals who needed the high level protection afforded by witness protection programs
- A middle ring of victims or witnesses to crime, and those who had helped the police in other ways, who had subsequently suffered non-life threatening intimidation
- An outer ring, comprising members of the public whose perception of the possibility of being threatened or harassed was such that they were not prepared to come forward with evidence to the police, even when they themselves were the victims of crime.
Several initiatives are directed at helping, advising and protecting victims and witnesses of crime from intimidation. Many states combat this problem by imposing tough penalties.