It was quite possible that if anyone was charged with the Amerithrax crimes, Kohl might seek the federal death penalty. But to bring a prosecution in a multiple murder case in which the murder weapon was a living microbe, the evidence would have to be tight and clear, persuasive to a jury, and sharp with proof—probatory, in the language of police work. There would not necessarily be any testimony from eyewitnesses. The crimes could have been perpetrated by one person acting alone, and so the Amerithrax case might have to be tried largely on forensic evidence: on the science squad’s work.

