It happens to the best of us. We’re in a hurry and make a snap decision. We fall victim to a candidate’s charms. Or, we believe what someone is telling us instead of looking to see the truth for ourselves. Whatever the cause, if you think you’ve hired a sociopath and he’s ruining your company, here’s what to do.

J.T. O’Donnell, founder and CEO of WorkItDaily​.com, suggests you use a few well-​known hallmarks to determine whether there’s a sociopath at work on your team. If people seem less than enthusiastic about working with a particular employee, or even hesitate to get in a car with him to travel to a lunch outing, ask yourself if he’s exhibiting the following kinds of behaviors.

Repeating Mistakes

Is this employee constantly telling customers they can have free shipping on their orders, even after you’ve told him that’s not company policy? He could be doing this to make life miserable for the customer service agent who has to take screaming phone calls about shipping charges that are showing up on client credit cards. In a twisted way, your sociopath takes pleasure in watching the agent struggle and he feels superior to her.

Lying

He may deliberately lie about something other employees have said or done. The lies come about often because he’s trying to make himself look better at someone else’s expense. Because he’s very charming, intelligent and manipulative, it may take you a while to catch on to his lies. And, by then, some of your best people have already left your organization.

No Apology

A sociopath will never apologize if you confront him about something he’s done wrong. When you try to show him proof about the situation, he’ll turn around the conversation and attack you.

If your employee is behaving in any of these ways, or has some of the other characteristics described by O’Donnell, tread carefully. The goal is to stay calm and focus on what you want – removing him from the company. Understand that this removal will not happen overnight and will require you to be detail-​oriented. Start with establishing exactly what you want the individual to accomplish on a daily basis. Sociopaths often can’t perform when someone else is setting the rules, so it won’t take long before he fails. Point out and document the failures. You may need to repeat this process a few times until you can build a case and show him the door.

The process won’t be easy, but stay on task and get the job done. And before you hire the next charming candidate who appears in your office, screen her personality with one of the many tools available to help you gauge how well she’ll fit into your group.