How to Write Liars Believably
The motive of every goal is the make the lie seem plausible while taking blame off the speaker, so liars will often project what they say to a third party: "Katie said that..."
Referring to third parties as "they" rather than he or she
In the case of a deliberate lie prepped beforehand, there will be an overuse of specific names (rather than pronouns) as the speaker tries to get the details right.
Overuse of non-committal words like "something may have happened"
Masking or obscuring facts like "to the best of my knowledge" and “it is extremely unlikely," etc.
Avoiding answers to specific, pressing questions
There's isn't a set tone/speed/style of speaking, but your character's speech patten will differ from his normal one.
People tend to speak faster when they're nervous and are not used to lying.
Constantly touching their nose
fidgeting, squirming or breaking eye contact
turning away, blinking faster, or clutching a comfort object like a cushion as they speak
nostril flaring, rapid shallow breathing or slow deep breaths, lip biting, contracting, sitting on your hands, or drumming your fingers.
Highly-trained liars have mastered the art of compensation by freezing their bodies and looking at you straight in the eye.
Trained liars can also be experts in the art of looking relaxed. They sit back, put their feet up on the table and hands behind their head.
For deliberate lies, the character may even carefully control his body language, as though his is actually putting on a show
Deceitful: those who lie to others about facts
2. Delusional: those who lie to themselves about facts
3. Duplicitious: those who lie to others about their values
Lying about values can be even more corrosive to relationships than lying about facts.
4. Demoralized: those who lie to themselves about their values
Genuine smiles or laughs are hard to fake
Exaggerations of words (that would normally not be emphasized) or exaggerated body language
Many savvy detectives ask suspects to tell the story in reverse or non-linear fashion to expose a lie. They often ask unexpected, or seemingly irrelevant questions to throw suspects off track.
