Employers routinely conduct internal investigations in response to allegations of harassment, discrimination, retaliation, theft, and other forms of employee misconduct. Although conducting such investigations can be critical to your continued operations, you should be mindful of the importance of exercising neutrality and fairness during the investigative process. 
Be thorough, but fair
An employer that exercises particularly aggressive interrogation tactics during internal investigations risks later allegations of intimidation and coercion by the employees who were interviewed. For example, the New York Times recently reported that auto parts retailer AutoZone has faced a series of lawsuits in recent years brought by former employees claiming they were pressured into providing false confessions after being subjected to intimidating interrogation techniques by the company. The legal claims in such lawsuits may include false imprisonment, invasion of privacy, defamation, and negligent or intentional infliction of emotional distress.
To reduce the risk of allegations of coercion, keep the following practical considerations in mind when you interview witnesses during investigations into employee misconduct:
- Have a trained investigator or HR employee conduct interviews.
- Define the scope of the investigation before you conduct any interviews, and consider preparing an outline of the information you’re seeking.
- No matter how sound the “evidence” may be, always interview the alleged wrongdoer and give him an opportunity to respond to the allegations.
- Ask the employee to come with you for the interview, but don’t order him to do so, if possible.
- Don’t threaten to call the police or make threats in general if the employee isn’t cooperating or refuses to answer questions. If an employee does refuse to cooperate, you may tell her that you will draw your own conclusions without her input.
- Advise the employee at the outset that he is free to leave the interview at any time.
- Consider having a second person at the interview to serve as a witness, if appropriate. However, keep in mind that having too many people present may increase the interviewee’s perception of intimidation.
- Be aware that union employees have the right to have a steward present during an investigative interview that could lead to discipline of the employee being interviewed.
- Interview witnesses identified by both the accuser and the accused; don’t selectively interview only the witnesses identified by one side.
- Exercise caution when using recording devices. Federal and state law restrict the use of audio and video recorders in certain circumstances.
In addition, you should be very careful when instructing employees to keep investigations confidential. In 2012, the National Labor Relations Board (NLRB) held in Banner Health System that blanket policies prohibiting employees from discussing ongoing investigations violate the National Labor Relations Act (NLRA). Instead, you must determine whether confidentiality is required case by case based on certain considerations, including whether the witnesses need protection, evidence is in danger of being destroyed, testimony is in danger of being fabricated, or there’s a need to prevent a “cover-up.”
Bottom line
Prepare yourself well before you interview potential witnesses during investigations into employee misconduct, and don’t use intimidating and threatening interrogation techniques. 
Although internal investigations are commonplace and often necessary, you can avoid decreased morale and an increased risk of litigation by conducting workplace investigations reasonably and fairly.
Randi J. Winter is an employment law attorney with Felhaber, Larson, Fenlon and Vogt, P.A. in Minneapolis, Minnesota. She may be contacted at rwinter@felhaber.com .