As federal prosecutors build a case against a Spokane man charged with sending ricin-laced letters to the president, the CIA, a federal judge and Fairchild Air Force Base, one of the legal challenges they’ll face is proving that the substance is indeed ricin, a lethal poison derived from ground seeds of the castor plant.
Beyond that, investigators also can use tests to figure out how the ricin was made, which can help link a suspect with the chemicals used in the process or determine how much advance planning took place. New versions of those analytic tests are being developed at the Pacific Northwest National Laboratory in Richland, at the Chemical and Biological Signature Sciences Laboratory.
Among the lab’s goals is developing better tools to identify the exact methods used to make ricin or other toxic substances, said David Wunschel, a biochemical researcher at PNNL.
There is an urgency to the lab’s work, because for many would-be terrorists, the ease of access and relatively simple production method has made ricin the “weapon of choice,” Wunschel said.
It’s not clear whether investigators here will use those additional tests – Spokane FBI spokesman Frank Harrill noted that simple possession of ricin is a crime.
Possession of its source, the castor plant, is not.
Castor seeds are typically used to grow the flowering plant, with several methods available for extracting ricin from mature castor beans.
On Wednesday, the U.S. Attorney’s office filed three criminal charges against Matthew Ryan Buquet, a 38-year-old Spokane janitor. He’s accused of developing and mailing ricin; of mailing a threatening letter to the president of the United States; and of sending a threatening communication to a Spokane judge.
Court documents say that a federal lab identified ricin in all five letters mailed by Buquet in May.
Wunschel said investigators can establish not just that ricin was made by a suspect, but they also can identify telltale chemicals from whichever method is used to make it.
That test is useful in cases where defense attorneys argue the poison was an inadvertent byproduct of attempts to make castor oil. That argument failed in a 2003 Spokane criminal trial that resulted in a 10-year sentence for a former Agilent software engineer.
Wunschel joined the PNNL staff in 2000. Following 9/11, the new Department of Homeland Security started funding projects to give law enforcement better tools in dealing with bioterrorism. The ricin study has been underway in Richland since 2005.
Scientists say extracting ricin from castor seeds may be relatively simple if someone follows a series of steps deliberately and carefully. But if someone uses a less-complex method with fewer steps, the result is a less pure and less lethal product, Wunschel said.
Ricin accounts for roughly 1 percent of the weight of the dry castor seed.
While only a small amount can be fatal, only one death has been publicly attributed to ricin. That was the 1978 London attack on a Bulgarian dissident who died after being jabbed with an umbrella that left a ricin-loaded pellet in his leg.
The scarcity of ricin-caused deaths may reflect “the lack of skill of the perpetrators more than anything. So we’ve been fortunate,” Wunschel said.
Ricin is a “one-to-one” attack that relies on getting a potential victim to breathe or swallow the toxin. Unlike poisonous gases or viruses, ricin isn’t absorbed easily through the skin.
Even so, the bioterror scenarios include the possible distribution of dozens of ricin-laced packages to a government office, causing a lot of disruption and requiring extensive cleanup, Wunschel said.
“So the impact of these cases is more economic, even though they’re generally not successful,” he said. “That’s why streamlining the investigation and adjudication process for these cases is probably one reason for the federal investment, since they are a national-level responsibility.”