Haley Robson was a 16-year-old South Florida high school student. When Jeffrey Epstein tried to grope her ... she brushed his hand away, Ms. Robson said in a 2009 deposition for a civil case. But she continued to visit Mr. Epstein's mansion dozens more times, in a lucrative new role: a recruiter of other teenage girls from her school. 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. Ms. Robson, now 33, is among them. This small cadre of women helped Mr. Epstein lure girls into his orbit and managed the logistics of his encounters with them. 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. Four women were apparently so instrumental to Mr. Epstein's operation that they were named as possible "co-conspirators" and were granted immunity from prosecution in a widely criticized plea bargain Mr. Epstein struck with federal prosecutors in Florida more than a decade ago. The four women - Sarah Kellen, Lesley Groff, Adriana Ross and Nadia Marcinkova - could still be subject to criminal charges in Manhattan. The United States attorney's office has said it is not bound by the Florida agreement.