Whoever sent 30 letters containing a cryptic message and suspicious white powder to churches, mosques and businesses in three states since August 5 is believed to be the same person or persons who sent white powder to government buildings in 2008.
Officials from the FBI say their suspect has sent a total of more than 250 letters since December 2008, when he targeted U.S. embassies and governors’ offices, according to Time.
In recent weeks, 25 of the letters were sent to addresses in the Dallas area and a further five were sent to Lubbock and Austin, Texas, Chicago and Waltham, Mass. The FBI and the U.S. Postal Inspection Service recently confirmed that the white powder inside the letters was harmless and that all of the letters shared postmarks from North Texas.
"The letters all have the same postmarks, the same content and similar return addresses that lead us to believe they are coming from the same person or persons," Special Agent Mark White told the Associated Press.
White did not elaborate on the contents of the message, but said it was typed, one line long and mentioned the terror group Al-Qaeda.
"Nobody understands what they’re trying to say," White said, according to the AP. "The message itself is unclear. But by taking that extra step and putting that white powdery substance in there, yes it’s considered a threat."
There is now a reward of up to $100,000 for information that leads to the arrest and prosecution of those responsible.