You'll recall the adage associated with behavior-based interview questions: Past behavior is a predictor of future behavior. Likewise, reference checks are critical for assessing past behavior to predict future behavior. Check the candidate's Reference Release form to find out whether or not current employers may be contacted, etc.  You are encouraged to contact current or former employers for information about the job candidate. 

HR can only verify dates of employment, job title, and salary in an employment reference check. Potential employers are usually seeking more information. If a current or previous employee gives the supervisor this signed reference release form, supervisors or managers may provide reference check information. By signing, the employee authorizes the release of any work-related information. It does not authorize the release of the employee's private information (SSN, date of birth, home address, etc.).

However, a supervisor or manager may disclose any work-related subjects, including but not limited to time and attendance, work product, work performance, work habits, skills, ability to form effective working relationships, and disciplinary records that have already passed the grievance time frame. When providing this information, the supervisor or manager must refrain from disclosing any medical or ADA information.