WASHINGTON—Revealing an increase in nontraditional family structures, a report released Thursday by the Pew Research Center found that more American children are being raised by carjackers who didn’t realize there was someone in the backseat. “The number of U.S. children reared by criminals who stole a vehicle by force and then left the scene unaware that a small child was in the rear passenger seat has almost doubled,” the report read in part, showing that since 2014 there has been a dramatic spike in the number of carjackers who made the choice to care for an infant they were surprised to discover in the back of the car after peeling out of an isolated, poorly lit parking lot. “Whether escaped convicts commandeer a vehicle only to find a sleeping toddler that they quickly bond with, or a thief suddenly begins to feel a parental responsibility to care for the innocent twins in the minivan he just stole, these living situations are becoming almost as common as the traditional nuclear family.” The report found that over the same period, the number of children being raised by infertile couples who kidnapped them from a maternity ward has steadily declined.