. On Monday (3/16/15), the White House Mail Screening Facility had received an envelope which was found negative on initial Biological testing. However, on the next day the chemical testing returned a presumptive positive for cyanide.  For final confirmation of the results, the sample has been sent to another centre of excellence. No adverse reaction has so far been noticed in the person at the mail-sorting facility who opened the letter. However, he is now under medical observation. Investigations are on the way now.