I am about to start a mystery novel and am thinking of using first-person present tense as the mystery unfolds
My concern is voice.
Your concern should be about the circular file.
I get these efforts on my desk and in my workshops all the time. First-person present will put you on the fast track to swift rejection unless you're a bloody awesome, and I mean *
AWESOME* writer.
It's used in the more arsty-fartsy literary novels or sometimes will pop up in a genre novel for a brief scene until the writer comes to her senses and gets back to a more readable style.
I've edited in the mystery genre, and am
not a fan of first-person present tense. This is my quirk, but a serious one. To me it's a sign of a writer who thinks no one's tried it before. It's as though the writer is inserting himself into the narrative, rather than letting the main character tell the story. Yes, it's nuts, but that's how it works in my mind.
I don't see it as adding to the suspense.
Does the MC survive to the end?? Of course he does, but he can do it just as well in first-person past tense which is easier to read for most people.
If you absolutely must have some, I would suggest a paragraph in italics at the chapter starts. Then you can indulge the urge without courting an outright rejection.
But--on the downside--you
have to make sure those bits do not slow the forward action of the narrative. You want the reader hurtling forward to the last page, and not give him an excuse to put the book down for the night.
Just so you know, I have used first-person present a few times in my stuff.
In them all, it was the result of the MC getting a head injury when the Bad Guy clocks him a good one. Once the MC recovered he was back to first-person past tense again.
And I wll also let you know that my editor was not even a little happy with me about those paragraphs. I also had to put in a special note to the copyeditor, letting her know that the tense-shift was done on purpose and that I'd not typed it while on a pub crawl!