Miami Beach police spokeswoman Vivian Thayer said Friday that the investigation found no corroborating witnesses, inconsistent statements by the alleged victim and no physical evidence.
A woman told police that on Sept.27 she became highly intoxicated while visiting Sharper's condo and awoke to find him sexually assaulting her. She didn't report it until January, after seeing Sharper on TV regarding a similar assault case in Los Angeles.
Sharper also is being investigated for alleged sexual assaults in Louisiana, Arizona and Nevada. Sharper has denied the allegations.
Sharper played for the Green Bay Packers, Minnesota Vikings and New Orleans Saints in a 14-year career.