Larry Nassar, the disgraced former doctor who spent decades molesting dozens of women and girls under the guise of medical treatment, will likely spend the rest of his life in prison. But how did he get away with it for so long?

In the video below, The New York Times explains that Nassar used a rare pelvic therapy that often involved vaginal penetration. The procedure was often times conducted without using a glove, gaining consent, or without a medical chaperone present -- all in violation of protocol.

Even after a complaint was made in 2014, Nassar's name was cleared and he was simply reminded to follow the established protocols.

But, the paper reports, complaints of Nassar's nefarious activities reached officials at Michigan State University as early as 1997.