In his single-bunk cell in the Ventura County Jail, on a concrete slab desk, Louis Gonzalez III found himself compulsively writing letters to his 5-year-old son. They were a chronicle of their truncated time together. Telling him how they’d cheered for the Yankees. How his favorite toy had been a mechanical garbage truck. How he’d been a picky eater from the start, but crazy for Cheerios. He never mailed them.