How Police Failed to Stop Former NFL Star Darren Sharper’s Cross-Country Rape Spree - ProPublica: And each of the cases involving Sharper, taken in isolation, presented prosecutors with hurdles. In secretly recorded phone calls with his victims, Sharper didn't make incriminating statements. He moved fast, in one city one day and in another the next. He drugged many of his victims with powerful amnesiacs, resulting in cloudy or even non-existent memories.
But taken as a whole, the Sharper case underscores American law enforcement's trouble with solving rape cases: Investigations are often cursory, sometimes incompetent, frequently done in ignorance of the suspect's past sex assault history.