In researching and publishing a book about them, I learned a great deal about child sexual abuse — enough to recognize that as horrifying as Nassar’s violation of young female athletes was, he and his crime spree weren’t anomalous. They snugly fit a pattern. And taking full and proper note of that is the best way — the only way — to protect children from the other Nassars out there.

These predators may not choose, as he audaciously did, to stalk gymnasiums and home in on future Olympic medalists. They may not use his particular cover and cast pitiless self-gratification as a healing touch. His case has harrowing details all its own, and that’s why so many people have responded to and discussed it as a singular and singularly shocking tale. Can you believe?

Oh, I can very much believe, because its outline and ingredients are completely familiar. Here we have an adult whose professional energies were largely devoted to children — and who was thus considered to have a special concern for, insight into and way with them. We have a figure of authority and expertise who seemed to be, and sometimes was, actually helping kids, so that their inclination — along with the reflexes of their parents and of their abuser’s colleagues — was to defer to him, trust him and give him the benefit of the doubt.

We have someone agile at cloaking impermissible physical contact in a banal or benevolent guise. And we had, around this individual, an institution so invested in its own reputation and unwilling to be distracted from its wider mission that it ignored clues, minimized accusations, hushed up accusers or did all of the above as the number of victims multiplied.

In Nassar’s case there were two primary institutions, U.S.A. Gymnastics and Michigan State University. Both behaved unconscionably. In the cases of the scores of priests whom I investigated, it was the Roman Catholic Church: its individual congregations, its dioceses, all the way up to the Vatican. The Boy Scouts organization was deemed so irresponsible that in 2010, a jury ordered it to pay $18.5 million to a former scout who had been abused in the 1980s. Athletic officials at Penn State, including the legendary head football coach Joe Paterno, disregarded warnings about Sandusky. In the short term, taking action is infinitely more uncomfortable and harder than simply wishing it all away.