You want an established accepted research tool that isn't impossible to administer, and that will give you analyzable data.  I would look at:

The Hare Psychopathy Checklist   http://en.wikipedia.org/wiki/Psychopathy_Checklist

http://www.hare.org/scales/pclr.html

It is a semi-structured interview, that covers antisocial behaviors including lying.

There is a self-report scale:  Validating the Factor Structure of the Self-Report Psychopathy Scale in a Community Sample

Others:

http://onlinelibrary.wiley.com/doi/10.1111/hcre.12019/full

http://psycnet.apa.org/psycinfo/2015-03429-001/

http://ajp.psychiatryonline.org/doi/10.1176/ajp.156.6.849

You can catch people being untruthful (if you know the ‘right answer’ by measuring pupillary dilatation.

Book: The Face of Lying

Gene Abel did this in pedophiles.  http://onlinelibrary.wiley.com/doi/10.1002/9780470061589.fsa1023/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false

Or you could develop your own scale: The Nixon Scale of Pathological Lying

Would I lie to you?

I suggest using a scale to measure the test group. The MMPI-2 develop a scale somewhat like the Psychological Testing: Minnesota Multiphasic Personality Inventory. Hopefully you should get the results you're seeking.

To my knowledge, there is no way to reliably test for dishonesty, particularly using a self-report tool. The MMPI-2 is a personality test that gives measure on 10 key personality traits. Built into it are some validity scales that indicate whether a person may be responding inconsistently in systematic ways ("faking good" or "faking bad", for example). These might be of some use to you, but must be interpreted with caution.

Thank you both. I had considered the faking scales from the MMPI-2, but I was hoping to avoid that particular tool due to it's length. I will keep looking, reviewing some more literature. 

You want an established accepted research tool that isn't impossible to administer, and that will give you analyzable data.  I would look at:

The Hare Psychopathy Checklist   http://en.wikipedia.org/wiki/Psychopathy_Checklist

http://www.hare.org/scales/pclr.html

It is a semi-structured interview, that covers antisocial behaviors including lying.

There is a self-report scale:  Validating the Factor Structure of the Self-Report Psychopathy Scale in a Community Sample

Others:

http://onlinelibrary.wiley.com/doi/10.1111/hcre.12019/full

http://psycnet.apa.org/psycinfo/2015-03429-001/

http://ajp.psychiatryonline.org/doi/10.1176/ajp.156.6.849

You can catch people being untruthful (if you know the ‘right answer’ by measuring pupillary dilatation.

Book: The Face of Lying

Gene Abel did this in pedophiles.  http://onlinelibrary.wiley.com/doi/10.1002/9780470061589.fsa1023/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false

Or you could develop your own scale: The Nixon Scale of Pathological Lying

Would I lie to you?

Thank you Gary, I will look into those. 

I do not know a specific scale for lies , only the validation of scales contained in Personalities instruments such as the MMPI -III and MCMI -III . Usually , pathological lying is associated with psychopathological problems identified with diagnostic criteria.

That's what I'm hoping to avoid, Carmen.  I want to do some research where Pathological liars are the test group, but I don't want to have to make them sit through the whole MMPI-2 or something similar as I will get a low response. 

Hi, you could consider the following scales:

- V.I.P. The Validity Indicator Profile (VIP; Frederick, 1997) is a two-alternative forced choice (2AFC) procedure intended to identify when the results of cognitive and

neuropsychological testing may be invalid because of malingering or other problematic response styles. The test consists of 100 problems that assess nonverbal abstraction capacity and 78 word-definition problems. The VIP attempts to establish whether an individual's performance in an assessment battery should be considered representative of his or her true overall capacities (valid or invalid). Performances classified as valid are classified as "compliant" and reflect a high effort to respond correctly. Performances classified as invalid are subclassified as "careless" (low effort to respond correctly), "irrelevant" (low effort to respond incorrectly), or "malingering" (high effort to respond incorrectly). 

from http://richardfrederick.com/assets/Frederick%20Crosby%202000.pdf

- Structured Interview of Reported Symptoms (SIRS-2)

Author(s): Richard Rogers, PhD, ABPP; Professional Manual by Richard Rogers, PhD, ABPP, Kenneth W. Sewell, PhD, and Nathan D. Gillard, MS

Publisher: PAR

Purpose: Assesses feigning of psychiatric symptoms

Age Range: 18 to 100 years

Admin: Individual

Time: Approximately 30-40 minutes

Retaining many of the features that made the original instrument the gold standard in its field and now including a new Spanish Language Interview Booklet, the updated SIRS-2 helps evaluate feigning of psychiatric symptoms in greater detail with expanded scoring and classification.

The SIRS-2 was developed to assess deliberate distortions in the self-report of symptoms. Each scale produces useful information on how a particular client may distort or fabricate his or her symptoms. The primary focus of the SIRS-2 is on the evaluation of feigning and the manner in which it is likely to occur, such as an exaggeration of symptom severity rather than a fabrication of symptomatology.

When using such a scale, would you consider the chance of false positives? As I assume that the odds for a false positive are much higher then for a hit, what would you give as feedback to your client?