"Based on preliminary forensic examinations, we assess with medium confidence that the IED was designed to fire directional fragmentation similar to a single shot shotgun with buckshot or cannon with a grapeshot round," the document, dated March 9, reads. "We likewise assess that the device was viable and could have caused personal injury or death."
March 9 was the day that law enforcement officials arrested Kevin William Harpham in connection with the device. Harpham has been charged with one count of attempting to use a weapon of mass destruction and one count of knowingly possessing an improvised explosive device.
The Joint Intelligence Bulletin indicates that the device was built with commonly available materials, and contained "fishing weights coated in rat poison." Law enforcement has not yet determined if any attempt was made to set the bomb off.
And while the bulletin says whoever built the bomb has a "higher degree of knowledge and skill than the typical domestic pipe bomb builder," the document also indicates that the device displayed a "low overall level of sophistication."