DALLAS — The FBI and U.S. Postal Service need the public's help in finding the person who has sent more than 380 letters filled with white powder to addresses in 48 states — including Texas — since 2008.
A reward of up to $150,000 is being offered for any information that leads to an arrest.
Federal officials are investigating seven white powder incidents across North Texas and a total of 20 across the state.
The latest incident in the Dallas area occurred last Tuesday when a suspicious letter was sent to a Dallas Head Start school. That followed similar letters with white powder addressed to schools in Irving, Garland and Mesquite and also to a church in Grand Prairie.
Hazardous materials crews tested the letters and found nothing dangerous.
Federal officials are concerned that the letter-sender has now started targeting targeted day care centers and schools.
"He's disrupting lives — not to mention the monetary loss," said Dallas FBI acting special agent in charge Kevin Kolbye. "It's costing millions of dollars for agencies to respond to these white powder letters."
Investigators said the suspect wrote "Al Qaeda back!" in one letter, but the FBI does not believe this person is linked to the terrorist group, but is rather using the language for shock value.
The letters use the phrase "Scooby Doo" to refer to the CIA and FBI. The suspect also made a reference to being a "triple dealer spy," and signed off as "SS Nazi FBI."
The FBI and the U.S. Postal Inspection Service said at a Wednesday news conference that the suspect is believed to be a male and may not demonstrate a mastery of formal English.
The suspect is thought to be wearing gloves when he mails the letters.
Anyone with information about the identity of the white powder suspect is urged to call 800-CALL-FBI or visit the FBI's online tips site.