Would this pragmatic law greatly reduce rapes on campus and elsewhere?

[GMTplus7]

As for outside of college, every state lets police hold someone for 48 hours without charging them, if they at least have probable cause. They rarely do hold men on rape charges since they doubt new evidence will surface. Rape is the one crime where you are not likely to be arrested.

It has nothing to do w the likelihood of new evidence surfacing. People get held in jail immediately if they are deemed to be a threat to public safety (armed robbery or guy who beat up his wife) , or a flight risk (white collar criminal suspected of embezzling $20 million).