Local officers passed on the information to the firearms bureau, which decided to begin its own investigation.
The firearms bureau dropped her as an informer a month later.
Officials with the firearms bureau in Washington said bombings nationwide appeared to be on the rise.
But a recent study by the firearms bureau demolishes that argument.
Hours after the arrests, the police and agents of the firearms bureau searched the men's apartment.
Lawyers for the firearms bureau declined to comment on why they agreed to release the information.
As a result, the weapon was not regulated by the firearms bureau and could be sold to civilians.
In building the computer models, the firearms bureau is trying to examine bomb damage, like the crater, and other evidence.
The firearms bureau essentially outlawed them for civilian use; no federal safety standard was ever created.
The firearms bureau did not provide the dealers' names, under the terms of the law allowing it to trace crime guns.