After Mr. Epstein’s suicide in a Manhattan jail cell in early August, federal authorities have refocused their investigation on the more than half-dozen employees, girlfriends and associates whom prosecutors say he relied on to feed his insatiable appetite for girls, according to two people with knowledge of the inquiry. Ms. Robson, now 33, is among them…

Mr. Epstein is also accused in civil suits of relying on an organized network of underlings: those who trained girls how to sexually pleasure him; office assistants who booked cars and travel; and recruiters who ensured he always had a fresh supply of teenage girls at the ready.

None of Mr. Epstein’s associates have been charged or named as co-conspirators in Manhattan. But federal authorities are eyeing possible charges that include sex trafficking and sex trafficking conspiracy, the two people with knowledge of the investigation said.