Who is Tom and Judy Gordon from Plum Island and what is their importance?

Tom and Judy Gordon are biologists who worked at Plum Island, and are murdered before the first chapter begins. The couple had been living on North Fork for two years with a nice house and boat. Friends of a local vintner, John had been at their parties several times. Tom once told John that his biggest fear was being kidnapped. At first, the investigation looks at this couple as a if they are terrorists, then opportunists, then drug dealers, and finally treasure hunters. In the end, though, John learns that the Gordons decided not to participate in Tobin's scheme to bilk the government, and that is what cost them their lives.