Federal agents charged a 42-year-old Iowa machinist with being "The Bishop," a shadowy figure who sent threats and unarmed bombs to U.S. investment houses in an effort to influence stock prices.
The arrest of John Tomkins "potentially saved lives ... before he posed any greater public peril," said Patrick Fitzgerald, the U.S. attorney in Chicago.
Tomkins was arrested in Dubuque on his way to work at a manufacturing company Tuesday morning, and agents then raided his home there, authorities said.
Tomkins had sent more than a dozen threatening letters to investment companies and individuals over nearly two years, including two unarmed pipe bombs that wound up in offices in Chicago and Kansas City, they said.
The bombs were "technically functional" but a wire had been disconnected from the battery in each case. Had the wires been connected "the device would have instantly exploded" causing property damage, serious injury or possibly death, according to a statement issued by the U.S. Attorney's Office in Chicago.
A criminal complaint filed in U.S. District Court in Chicago said a letter accompanying the devices declared: "The only reason you are still alive is because I did not attach one wire ... imagine how you will feel when I mail that same package to one of your family members ... if you want to keep the people around you safe, you will do as I say."
The case had caused concern throughout the U.S. financial services industry.
Authorities said they were able to crack the case in part because of records supplied by the Securities and Exchange Commission showing Tompkins as the only individual investor in 3Com
One typewritten letter sent to an investment company executive stated how easy it would be to kill someone and demanded that the price of 3Com stock be raised to $6.66 by Oct. 31, 2005.
The unarmed pipe bombs were received in the mail in January by American Century Investment Management in Kansas City and Perkins, Wolf, McDonnelland Co. in Chicago. The latter device had been addressed to Janus Capital Group in Denver but was forwarded to Perkins, which is a subadviser to Janus.
American Century spokesman Chris Doyle said Wednesday the company was relieved an arrest had been made.
"We're optimistic. We hope this is the guy," said Doyle. Authorities said 16 other threatening letters had been mailed to investment companies and associated individuals since May 2005.
The arrest followed an investigation by more than 100 Postal Inspectors, joined by agents from the FBI's Joint Terrorism Task Force and the Bureau of Alcohol, Tobacco, Firearms and Explosives.