reactor. >> the sample can be analyzed as is in most cases, just simply weighed into a radiation vial. most other methods require dissolution of the sample. >> when scientists examine the hair with gamma ray spectrophotometry, they discovered a startling piece of information. nancy had ingested small doses of arsenic every week starting four months before her death. the dose of arsenic increased four weeks before her death. the highest amount of arsenic was in nancy's system two weeks before her death. >> her levels were anywhere from 4 to 100 times what normal levels were, so, it was a very significant level and it was lethal. >> the forensic tests showed the poisoning started when nancy's husband, richard, moved back home after the separation. but richard wasn't the only person in nancy's life who had both motive and access. nancy's handwritten diary