In today’s competitive workforce, candidates will go to great lengths to get a second look from a hiring manager. They may even lie.

In fact, one in four candidates have exaggerated the truth to get hired, according to a new International survey of 800 employed adults conducted from May through July by First Advantage.

Unfortunately, some are so good at lying, it’s tough for employers to tell a dishonest employee from the real deal. Employers need to learn how to spot these liars before they make the mistake of hiring them. Here’s how to catch dishonest candidates before it’s too late:

1. Test candidates’ skills.

A shocking 58 percent of candidates have been caught lying about the skills they have on their resumes, according to a survey of 2,188 hiring managers conducted in May through June 2014 by Harris Poll on behalf of CareerBuilder.

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Find out what candidates are really made of by testing their skills either before or after the interview. It’s better to find out sooner than later. Use an app such as Interviewed to administer job simulations such as customer service or tech support, or tests in accounting, typing and math for retail.

2. Contact references, really.

CareerBuilder’s survey also found candidates lie about other things on their resumes, including dates of employment (42 percent), job title (34 percent) and companies for which they worked (26 percent).

In fact, one employer surveyed recalled, “an applicant who listed three jobs over the past several years. Upon contacting the employers, the interviewer learned that the applicant had worked at one for two days, another for one day and not at all for the third.”

The lesson? Don’t brush over references. Contact previous employers to ask about dates of employment, responsibilities and overall performance. If possible, call. Phone calls will reveal verbal clues such as hesitation or unease, which may mean the reference is unsure of what to say or afraid to speak badly about the candidate.

3. Research candidates online.

One search on social media can reveal everything employers need to know about a candidate. In fact, Jobvite’s 2014 Social Recruiting Survey found 55 percent of recruiters have reconsidered a candidate based on what they found on his or her social-media profile, and 61 percent of those reconsiderations were negative.

Check out all candidates’ social-media channels to get a feel for who they really are and what they value and believe. Look at work history, volunteer experience and what their friends have to say about them. If it doesn’t align with what’s on their resumes or cover letters, move on to someone else.

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4. Perform background checks.

Nearly half of respondents in the First Advantage survey said when an organization administers background checks, it raises the credibility of the organization. The same amount also said it helps them trust their colleagues and the organization. Forty-two percent said it makes them feel safer at work.

Background checks should be a required part of the interview process, no matter what. To simplify the process, use a tool such as KlinkCheck to receive a high-quality, in-depth background analysis on all applicants.

Performing background checks will not only help boost the employer brand demonstrating safety, but it will show existing employees the organization’s leaders care about who they let join the team.

5. Trust that first instinct.

A study from UC Berkeley, published in the Journal of Psychological Science in March 2014, shows lies can be accurately detected when less conscious mental processes are used -- meaning when people don’t over-think a situation.

Don’t ignore that feeling that says “something isn’t right” when first meeting a candidate. Though mysterious, the mind is a powerful thing. Don’t second guess or over-think if something feels off. Trust that gut feeling.

What are some other ways to spot a liar before you hire? Share your suggestions in the comments section below.

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