Every employer has a moral and legal duty to protect the business and its employees both from illegal misconduct and from actions that create a hostile work environment. Conducting an investigation anytime you receive a complaint or have reason to believe an employee is engaging in misconduct is vital to fulfilling these responsibilities. Unless you have valid reasons for not doing so, informing involved parties that an inquiry will be taking place is a common first step.

Internal Memo Format

Although you can draft the letter using a memo or business letter format, a memo is more common for internal communications. In addition, the title or subject line typical in a memo can make this format more effective. Besides the title line, a memo also includes the date, the name of each recipient and the sender's name and title. Left align and single-space each paragraph in the body of a memo and use a double space between paragraphs. Include special notations to mark the memo as confidential and to indicate whether the memo includes any attachment or enclosures.

The Accused Employee

Notify the accused in writing before the investigation begins. The letter of investigation should explain the allegations in as much detail as possible, including names, dates and circumstances. Describe the investigatory process, identify legal rights the accused person may have and tell the accused person he’ll have a chance to tell his side of the story both in writing and during a personal interview. Tell the person whether it’s “business as usual” or whether his role or job duties require modification until the investigation is complete.

Pending Investigation Notification

Include the employee’s immediate supervisor and the department manager in an initial notification. The letter should explain the nature and scope of the pending investigation. In addition, the letter should outline steps to be taken before the investigation begins, such as accounting for and safeguarding business assets and property or modifying an employee’s duties. Finally, the letter should state whether supervisors and managers will participate in the investigation, and if so, define specific roles and responsibilities.

Investigation Interview Letters

Letters also should go to anyone you plan to interview as the investigation proceeds. However, unlike a pending investigation notification, which may include more than one recipient, interview notifications should include a single recipient in the address line no matter how many letters you send. The letter should provide no specific details, but instead simply state that the employee may be interviewed as part of an ongoing investigation, provide the name of person who’ll be conducting the interview and set a full-cooperation expectation. In addition, the letter should state the memo is confidential information and not appropriate for inter-office discussion.