An organization should be particularly careful in its screening of individuals, such as those under consideration for employment, who might be given access to the system. Potential employees should be subject to intensive background investigations to ensure that all statements with regard to previous experience and education are accurate and complete. Several specialized firms perform independent checks and can verify statements regarding education, employment history, and criminal records. Character references should be obtained and verified. Personal impressions are valuable also; it is advisable to have several staff members meet with job candidates to obtain their impressions.