Matthew Ryan Buquet, a 37-year-old janitor and a registered sex offender, was charged last week with mailing a threatening communication.

WSJ: 'The perfect poison': Ricin used in 3 recent cases

Last week, FBI agents arrested Matthew Ryan Buquet after a grand jury charged him with mailing threatening communication to a senior judge in the U.S. District Court for the Eastern District of Washington state.

CNN: Threatening letters to Bloomberg test positive for ricin

"We really need to focus on homegrown small businesses, incubated businesses that will create an identity in our city and be proud to be here, " said Matthew Ryan, mayor of Binghamton, the largest city in Broome County.

WSJ: Dreams of Binghamton