You are the head of fraud risk management for a company that provides telecommunications services to business customers Recently an employee in the customer service department has approached you with concerns about a rise in customer complaints concerning overbilling.

In the past three months an increasing number of clients have complained they have been charged for unspecified "administrative fees beyond their contracted rates. You inquire with your company s operations department about these administrative fees but they are not aware of any changes to services or policies that would have led to new fees for customers After conducting an audit of customer billings you discover that the issue is widespread and you suspect it may be part of an internal fraud scheme on the part of one or more employees.

You initiate an internal investigation of company employees. Which employee should you investigate FIRST?