Knapp (D) was being tried for aiding and abetting Crowninshield for the murder of Joseph White. The Commonwealth (P) claimed that D aided and abetted Crowninshield who actually struck the fatal blows. In order to establish D’s guilty, it was essential that P prove Crowninshield’s guilt. However, Crowninshield had committed suicide before the trial and the Prosecution, under Daniel Webster, discussed the probative value of the suicide on the issue of Crowninshield's and thus D's guilt.