A dispute between two Gypsy clans over control of the fortunetelling trade in Newport Beach, Calif., has spilled into court, offering a rare glimpse of an insular culture that has long settled arguments according to its own Old World rules of honor.

The dispute in well-to-do Orange County has unfolded like a gangster movie, with allegations of death threats, a graveside scuffle and nicknames like “White Bob” and “Black Bob” — details revealed in a police report and requests for restraining orders.