Michael Connelly, a former Los Angeles Times reporter turned novelist, writes some of the most readable mysteries being published, and I thought this one of his best.
It features his main series character, police detective Hieronymus "Harry" Bosch. ("Lincoln Lawyer" Mickey Haller appears in a supporting role.) Bosch, now in his mid-60s, is working as an unpaid reserve detective for the San Fernando police department, having burned some bridges with the LAPD where he used to work. He loves being a cop and doesn't mind doing it for free, and he has enough money that he doesn't need an income, though he does take on private investigator work from time to time.
The plot involves two separate cases, one for the San Fernando department involving tracking down a serial rapist and the other a job for a private client, a very aged billionaire who wants to learn if the child he fathered in his late teens might still be alive. Both stories are suspenseful in different ways.
His website says Connelly has two more novels coming out this year. In addition, there's a Bosch television series in its third season on Amazon.