The correct answer is spectral evidence. The Reverant Cotton Mather was not directly involved in the Salem witch trials. However he wrote one letter to Magistrate John Richards of Boston. Mather urged caution in the use of "spectral" evidence. Supposedly the devil could assume the shape of an innocent person. Unfortunately, instead of heeding the warning against using supernatural evidence to convict accused witches, the magistrate and the courts interpreted the letter as a sign of Cotton Mather's approval of the persecution. Mather also wrote a controversial book, The Wonders of the Invisible World in which he does not condone the use of spectral evidence used to to convict the witches. However, the most intriguing detail about this book is in the foreward. Mather writes, "I live by Neighbours that force me to produce these undeserved lines". Mather endured public shaming for the rest of his life, being considered as a witch hunter. In a diary entry,he expressedconcern about God taking revenge on his family because of his failure to stop the trials.