One more insight into how Michael Connelly writes, from an article in Writing Magazine. This one is about how he developed the character of Mickey Haller, the protagonist of "The Lincoln Laywer":
He says, "I had been inspired to write a character, who was a lawyer working out of the back seat of his car, by a real lawyer who works out of the back seat of his car. For about five years I had been thinking about that character and how I would write him. It wasn't something where I was taking notes or writing outlines, it was just that I knew I was gong to write about him at some point. Little by little I accumulated some anecdotal stories, some ideas about how he would work and talk and then finally, I started writing."
If you're not ready to start writing, at least let your characters live and grow in your head and the day will come when they insist on bursting out onto paper!
(For guidance in writing your book, see my book, "Your Writing Coach" from the usual sellers.)