I've recently had the pleasure (although the subject matter was less than pleasurable!) of working with the lovely Éanna Hardwicke on a series for the BBC. We had to create the voice of a young man convicted of murder, who displays psychopathic tendencies. We were intrigued to discover that these tendencies have a profound impact on the voice. So here's part of a list, originally published in Psychology Today in 2019, just in case you ever meet one! :-
Creating complex and often convincing lies
Charming the listener
Talkativeness
Attempt to dominate the conversation
Occasional stuttering when the topic touches on their vulnerabilities
Sudden shifts in the subject of conversation when they do not feel in control
Leaning in and frequent use of hand gestures
Non-genuine emotional expressions
Few emotion (especially fear) related words
Expression of emotions unrelated to the context/topic
Drawing conclusions based on limited information
Hinting at factors the listener knows nothing about
Black-and-white worldview
Tendency to generalize
Self-contradictions
Omitting essential details
Greater use of past tense
Greater usage of nouns and personal pronouns