Farrar moved out immediately upon Green 's return home .
Farrar had researched castor beans in the interim and came to the conclusion that Green had poisoned his food with the ricin that could be derived from the beans .
Farrar , who had researched castor beans in the interim and came to the conclusion that Green had poisoned his food with the ricin that could be derived from the beans , moved out immediately upon Green 's return home .