What personality traits do you look for in a person to make sure that he or she is not another Bernie Madoff?

Dr. Gerald Bryant, a psychiatrist specializing in the criminal mind at the Forensic Psychology Group may have the answer.

Madoff is serving a life sentence in federal prison for perpetrating a $50-billion Ponzi scheme -- the largest in U.S. history.

Dr. Bryant told International Business Times that Madoff and other perpetrators of massive fraud typically suffer from narcissistic personality disorder (NPD), a condition in which the sufferer is absolutely convinced that he or she is better than everyone else.

“He, and others like him, most likely believe that no matter what they do they are justified in doing it and won't get caught,” said Bryant.

He added that the fact that it took so long to catch on to Madoff’s scam simply verified in Madoff's warped mind that there was nothing wrong with what he was doing.

“Authorities looked at Madoff a number of times and didn’t do anything, and so [Madoff’s] crimes became substantiated in his mind, Dr. Bryant said. He most likely felt no remorse over what he had done whatsoever.”

Bryant listed some behavioral trends to look for in order to differentiate between a legitimate money manager and a snake oil salesman.

“Madoff and people like him are usually self-assured to a degree where it stops being rational,” said Bryant.

“People like Madoff are usually gregarious to the point where it’s almost cartoonish. Madoff would make it a point to show you how good his personal life is, how rich he is, and how he’s living a lifestyle that’s out of reach for 99.9 percent of the people.”

Indeed, Madoff owned a yacht, two private jet planes, and a penthouse apartment in Manhattan, all bought with stolen money.

Dr. Bryant also said that while Madoff probably liked to be around other people, he probably wasn’t personable.

“He would, at first, come across as being a very open person who wants to include those around him in his circle. But once you’re in, there will be no personal contact. He’s the type of person whom you can talk to a lot but never really get to personally know.”

After Madoff was convicted and sentenced to life in prison, people who knew him described him to reporters as being “reclusive, at times standoffish and aloof, and closely attuned to his own image.”