On Monday, a series of threatening letters filled with an unknown powder started showing up at financial institutions across America, causing a massive response and ensuing multi-agency investigation led by the FBI and the U.S. Postal Inspection Service in concert with state and local authorities.

It’s a pending investigation, but here’s what we can tell you:

… So far, we’ve identified more than 50 letters, nearly all of which use threatening language identical to the text shown above. The letters have all been mailed from Texas and postmarked at Amarillo.

… Most of the letters contained some sort of powdery substance. All field tests to date have turned up negative—the powder appears harmless. Additional testing is taking place at regional laboratories.

… The letters have been sent to at least 11 states, including Arizona, California, Colorado, Georgia, Illinois, New Jersey, New York, Ohio, Oklahoma, Texas, and Virginia.

… The following three institutions have received letters:

• Chase Bank;
• The Federal Deposit Insurance Corporation, or FDIC, an independent federal agency; and
• The U.S. Office of Thrift Supervision, which regulates all federal and many state thrift institutions.

You can help. Please study the images above and see if you recognize the phrasing of the letter, the envelope label, or any other clue that you think might help investigators. The U.S. Postal Inspection Service is offering a reward of up to $100,000 for any information leading to the arrest and conviction of the person or persons responsible. 

If you have any information about the letters or if you know who might have sent them, please contact authorities immediately in one of the following ways:

• Call the FBI toll free at 1-800-CALLFBI;
• Contact your local FBI office;
• Submit a tip anonymously on our website;
• Contact the U.S. Postal Inspection Service at 1-877-876-2455.

Meanwhile, we’d like to remind everyone that sending a threatening letter with or without powder—even if it’s a hoax—is a serious crime. It demands a multi-agency response in each location, causing a drain on resources and diverting personnel from actual emergencies and other urgent situations.

“People who have mailed these kinds of hoax letters in the past have received some serious jail time,” says Special Agent Richard Kolko, Chief of the FBI’s National Press Office in Washington, D.C. “This investigation will continue until those responsible are arrested, and we appreciate the public’s support by providing information.”