There have been bigger trials with splashier consequences, but for pure drama – and a window on the way entrenched privilege works in the US south – the events unfolding this week at the Colleton county courthouse in Walterboro, South Carolina, are hard to match. In the dock: the 54-year-old Alex Murdaugh, scion of a legal dynasty stretching back 100 years, who has been found guilty of murdering his wife and son. That is the matter at hand and it is lurid enough: 22-year-old Paul Murdaugh and his mother, Maggie, found shot to death in 2021 in the grounds of the family’s hunting lodge, 65 miles west of Charleston – killed by Alex, say prosecutors, to distract attention from his financial crimes. Behind the double murder, however, lies layer upon layer of further alleged criminal activity, from vast embezzlement from the family law firm, to cover-up, to the involvement of Paul in a drunken boat crash in which a 19-year-old died, and for which the 22-year-old was facing trial at the time of his murder. Three months after the killings, someone shot Alex Murdaugh in the head – an act, it is alleged, that Murdaugh commissioned himself, paying a gunman to kill him so his surviving son could collect on insurance. Meanwhile, the death of the family housekeeper in 2018 has been the subject of renewed police interest. The story, currently the subject of Netflix and HBO multi-part documentaries, would seem so wild and convoluted as to illuminate nothing beyond itself, were it not for the influence of the Murdaugh family. Going back to the 1920s, Alex Murdaugh’s great-grandfather, grandfather and father – respectively, Randolph Murdaugh, Randolph Murdaugh Jr, and Randolph Murdaugh III (Alex Murdaugh’s older brother is Randolph Murdaugh IV) – all served as top prosecutors across a five-county district, an area of about 8,300 square kilometres (3,200 square miles) over which they had responsibility for all criminal prosecutions. So great and far-reaching was the power of the Murdaugh name that locals in that part of South Carolina refer to it as “Murdaugh country”. Alex Murdaugh, a lawyer at the family firm he is charged with defrauding, stands accused of being the embodiment of what happens when people are cushioned over generations from the consequences of their own actions. That this story unfolds in the south, cradle of the good-old-boy network of near-oligarchical governance, is no coincidence. I happened to be in South Carolina last week and it’s very beautiful, but woo, to an outsider, it’s intensely weird. White tour guides lead white tour groups around downtown Charleston, cheerfully pointing out where enslaved people were sold, before pulling up at the gift shop. Plantation houses, mindful of how times have changed, invite visitors to consider a single slave dwelling on their properties, while advertising the grounds as the “most beautiful gardens in America”. Use of the passive voice – these houses are “witness to history”, according to the marketing bumf, which is certainly one way of putting it – is rampant. Many of the people Alex Murdaugh is accused of defrauding were poor, Black clients seeking personal injury compensation through his family’s law firm. Two of these alleged victims were the sons of the Murdaugh family’s longtime housekeeper and nanny, Gloria Satterfield, who died after an accident in the Murdaugh home in 2018. It was believed Satterfield was tripped by the family dogs while walking up the brick front steps, hitting her head and dying a few weeks later of her injuries. When the Murdaugh family’s insurers awarded a $4.3m settlement to Satterfield’s sons, they never saw a penny. In October 2021, four months after the murder of his wife and child but before Alex Murdaugh was charged with their killings, he was arrested in connection with the missing money. He later admitted he owed the Satterfields the full settlement. So it goes on. At an earlier hearing, one of Alex Murdaugh’s lawyers used as mitigation his addiction to painkillers, inviting the judge to look upon Murdaugh’s sorry face as the encapsulation of what the opioid epidemic has done to the US. This was, surely, an accurate statement, just not in the way the lawyer intended. If Murdaugh represents some aspect of American life, it is one that is as old as the country itself. Emma Brockes is a Guardian columnist