The traces of ricin were revealed to be the atmospheric norm.
A deadly poison, ricin, comes from seeds of the castor bean.
The poison used in both cases was ricin.
He was questioned by police as to why he had such a large quantity of ricin.
During the court proceedings, prosecutors drew attention to the ricin segment, stating that the men were collecting information on the manufacture and use of ricin.
Ricin is easy to produce, but is not as practical nor likely to cause as many casualties as other agents.
Police tipped off the authorities that traces of ricin had been discovered.
There was no one who even knew how to purify ricin.