More on John Preston's Miracle Florida Police Dog

Last month, I blogged on a series of DNA exonerations of men convicted of rapes in the early 1980s due to the extraordinary claims of Florida police dog handler John Preston, now deceased. Now a fourth conviction has been called into question.

Questions about Preston's miracle dogs have persisted for two decades. See, for example, the jaw-dropping Geraldo Rivera 20/20 segment below. One state's attorney even resigned in protest, stating he wouldn't be a part of his colleagues "manufacturing evidence."

Yet prosecutors continued using Preston. And still today, even after the exonerations, Florida's governor, attorney general, and the state's attorney for Brevard County (where Preston mostly testified) refuse to open an investigation to see if any other convictions may have been tainted by his testimony.