Wow. Can this man with his extensive education and background and work experience be able to sort out fiction from lies? Surely he can, but this is a new challenge for him. He's never had an investigation like this. But he does have plenty of money and a dream-team of legal eagles on his side. Personally, I think he will eventually cut through all the lies, deceits and cover-ups but it will take time.
As writers we are hoping to be as Lawrence Block (a belated happy birthday, Larry) titled his book, Telling Lies For Fun And Profit. We are liars of the first, second, third and last order. And, boy, do we have fun doing it.
Just a couple of things to remember. If we have a character who is a police officer and we interrogate people to find out who committed the crime, do we rely on the old stand-by like body language? Do we express that? How the suspect, slouched and seemed uninterested.
Does our amateur sleuth draw any conclusion from the person who will not look directly into the character's eyes. That is another basic "tell" of a liar.
Do we ask the right questions in order to catch the suspect in a lie? Of course, we do these things. And Class, be sure you set things up so that you either have an idea the suspect is lying. Or have your character acknowledge that he or she knows they need more proof.
Most parents have a built in bull-pucky meter in their head and know almost instinctively when their child is lying. If that's true then your character might even say or think that. It's doesn't guaranteed they know when a suspect is lying.
You know, as a writer you must make your story or book believable so be sure and check on the reality of your character either detecting a lie or missing it altogether. If your character misses it then be sure you set it up that way.
If all else fails, have your suspect take a lie detector test. I remember Very Special Agent Tony what's-his-name in the NCIS TV series telling a suspect once that every time the man lied, his (meaning Tony's) ears would itch. Tony had proof of part and part he suspected, but scratched his ears at the right time and the suspect confessed. Makes me laugh every time I think about it. And I do know Tony's last name, I just am not sure of the spelling at the moment.
I realize most of you reading this are published writers. Most also have awards and honors for writing excellence. But gentle reminders of details are always welcome in my book. Just continue telling and detecting lies because that's what we do.