( CNN ) -- A San Francisco man accused of possessing bomb-making materials in his apartment also bought lethal toxins online , the FBI said in documents unsealed Friday . Ryan Kelly Chamberlain II was charged this week with possession of an illegal destructive device . Bomb technicians found a series of items in his house , leading to a manhunt that ended with his arrest Monday . Items included a powdery , green explosive substance , a model rocket motor , ball bearings and an igniter for home-made bombs , according to a different affidavit unsealed earlier this week . It did not list deadly toxins at the time . But the latest documents detail lethal poisons bought anonymously in dark , encrypted corners of the Web . `` The investigation has revealed that Chamberlain has utilized an anonymous , Internet-based market place known as Black Market Reloaded to facility the unlawful acquisition and possession of biological agents and lethal toxins in California and Florida , '' FBI agent Michael Eldridge wrote in the latest documents . Chamberlain bought abrin from a seller in Sacramento in December , the documents allege . He said he planned to use the poison to `` ease the suffering '' of cancer patients , according to the documents . Abrin is a natural poison found in the rosary pea plant . It 's similar to ricin , but has never been used in terrorist attacks , according to the Centers for Disease Control and Prevention . In addition , he allegedly bought ground rosary peas and pure nicotine in December and June of last year , respectively . Nicotine can be used to poison food and water , according to the CDC . Chamberlain , 42 , was arrested near the Golden Gate Bridge after a three-day manhunt . It 's unclear if he 's entered a plea . Authorities had been looking for him after searching his neighborhood on a tip that he had `` items of great concern '' at his home , FBI Special Agent in Charge David Johnson said . He declined to say what Chamberlain planned to do , if anything , or what motivated him . If convicted of the illegal destructive device possession charge , he faces up to 10 years in prison and a $ 10,000 fine .
He was charged this week with possession of an illegal destructive device . FBI : He bought lethal poisons in dark , encrypted corners of the Web . They included abrin , a poison similar to ricin .