The inspectors of the JIM, who were unable to visit Khan Shaykhun, based their findings on "sufficient credible and reliable evidence" of Syrian aircraft that dropped munitions, the crater that was caused by the impact of the aerial bombing, interviews with victims, and their finding that sarin identified in the samples taken from Khan Shaykhun was most likely been made with a precursor (DF) from the original stockpile of the Syrian Arab Republic.