In his green and white striped prison garb, Richard Scott Smith, the slimy con man at the centre of Showtime's Love Fraud documentary, tried to explain that he was "only looking for love."

Although he worked hard to be convincing, when he opened his mouth, it was easy to see why everything sociopaths say is manipulation.

Smith had married 10 women — twice committing bigamy — and took all their money. He scammed additional women without actually marrying them. The victims found each other via a blog, then banded together to bust him.

What did Smith say about that? "I'm not the person they claim me to be." Really?

"I wanted the serious," he said in his jailhouse interview. "I wanted the long term. I wanted some permanence in a relationship. I wanted a fairytale romance. I want forever."

How did he pursue his romantic aspirations? By telling three or four women at a time that he loved them and wanted to marry them.

Multiple people interviewed on the Love Fraud show described Smith as a sociopath, and I think they're right. So, why would this man agree to be interviewed at all?

Probably he believed he would be able to talk his way into — or out of — whatever he wanted. After all, he'd been doing it successfully all his life.

Sociopaths share common traits.

As author of Lovefraud.com (not affiliated with Showtime's Love Fraud documentary), I've conducted multiple surveys, and have published scientific research about the behavior of sociopaths in relationships — especially those with antisocial and psychopathic personality disorders.

I've found that the most common traits are: 

• Deceitfulness
• Callousness
• Manipulation

Sociopaths are parasites.

They live by exploiting others. Often they want money, but not always. They may target you for a place to live, services like cooking, housekeeping, or childcare; a respectable image in the community; or simply to entertain themselves.

Like Richard Scott Smith, they're often successful at getting what they want. How do they do it? Through manipulation.

Like Richard Scott Smith, they're often successful at getting what they want. How do they do it? Through manipulation.

Most sociopaths, although not all of them, have the gift of gab. The words that come out of their mouths sound smooth, convincing, and authoritative, even though they leave you totally confused.

That's because everything sociopaths say is manipulation.

Here are 5 key concepts for spotting sociopathic manipulation.

1. Check for lies. 

All kinds, even those that don't make sense.

Sociopaths lie like they breathe. They tell big lies, little lies, stupid lies. They lie when they'd be better off telling the truth. The objective of the lie is to get what they want, or to keep you off-balance so you give them what they want.

Unfortunately, it works. Research shows that human beings can spot lies only 53 percent of the time. Usually, you don't realize sociopaths are lying until it's too late.

2. Be aware of ulterior motives.

Sociopaths are always plotting and scheming. They view every interaction as a potential opportunity to get something that they want.

Even if they appear to be helpful and caring, there is an ulterior motive. Perhaps they're buttering you up to exploit you later. Or they do something for you so that you feel indebted to them.

Sociopaths never do something because it's the right thing to do — there's always an agenda.

3. Watch out for entitlement.

Sociopaths have an amazing sense of entitlement. They believe they are entitled to get what they want, when they want it and how they want it.

They have no qualms about crushing any person, object, or situation that stands in their way. Their preferred strategy is to manipulate you into giving them what they want, but if necessary, they will employ other tactics, such as theft or violence.

4. Be wary of sob stories to exploit your sympathy.

One of the most powerful manipulation strategies that sociopaths employ is getting you to feel sorry for them. They may tell you about their abusive childhood, tyrant boss, or crazy ex, all to pluck at your heartstrings.

Then, when you are sufficiently sympathetic, they explain how you are the only one who can help them. You give them what they want, which was the objective all along.

5. They change their behaviour to match the person they're trying to influence.

Sociopaths are chameleons — they make themselves into whatever they need to be in order to get what they want. Many Lovefraud readers have told me they watched a sociopath change right before their eyes, depending on whom they were trying to influence.

When you're the target, they figure out what you are looking for, and then turn themselves into that person. They engage in serious impression management.

Sociopaths are supremely confident in their ability to convince people to believe what they want them to believe and to do what they want them to do. But in the end of the Love Fraud documentary, Richard Scott Smith overplayed his hand.

During his jailhouse interview, Smith used the standard sociopathic manipulation tactics. Asked why he moved his relationships along so quickly, he blamed it on his anxiety.

He said he worried that the woman would change her mind, meet somebody else, somebody better. He said he didn't want to lose anyone else, that he had a big fear of people leaving him.

Cue the violins. Then he engaged in denial. Smith proclaimed that he hadn't committed any crimes, and he was wrongly accused of everything.

He tried righteous indignation. Asked what he would say to the women who wrote the blog about him, he said they made his life difficult, but that he maintained his integrity and forgave them.

The problem, of course, was that his cover was already blown. Everyone watching the show knew what Richard Scott Smith had done, and how his victims were affected. It was easy to see his manipulation.

But when you don't know a person's backstory and true character, which is the situation every time a sociopath starts working on a new target, well, sociopathic manipulation is highly effective.

That's why it's important to know the tactics, so you can spot them and escape before too much damage is done.