White powder letter probe costing millions of taxpayer dollars, federal authorities say

Federal authorities say they hope to solve the worst white powder mailing case in U.S. history because the letters are tying up first responders and costing taxpayers millions of dollars.

Amanda McMurrey of the U.S. Postal Inspection Service says authorities believe the same person has sent nearly 400 letters containing non-toxic powder to locations across the country and abroad from Texas over the past four years.

She says officials have found similarities in the letters and the way they were mailed, but the suspect has proved elusive in part because no finger prints have been discovered.

McMurrey says while no one has been harmed, each incident diverts fire department personnel and resources.

Investigators say two suspicious letters reported Thursday aren't connected to the case.