SPOKANE, Wash. -

An unclassified Joint Intelligence Bulletin written earlier this month gave an in-depth analysis of the MLK Day bomb and described the maker of the MLK Day Bomb as someone who ?possesses a higher degree of knowledge and skill than the typical domestic pipe bomb builder.?

The Joint Intelligence Bulletin, issued by the FBI and the Department of Homeland Security, was issued as an ?Unclassified / Law Enforcement Sensitive? report on March 9 in the wake of the arrest of Kevin Harpham by the FBI Hostage Rescue Team near his home in Addy, Wash.

According to the bulletin, the forensic analysis conducted by the FBI crime lab in Quantico, Va., determined that the device was a radio controlled improvised explosive device (RCIED) that was designed to fire ?directional fragmentation similar to a single shot shotgun with buckshot or cannon with a grapeshot round.?

The analysis indicated that the weapon included a steel pipe with a black powder main charge inside a plastic bag housed in a section of a PVC pipe. The report says that while, not confirmed, it appears the initiator was a rocket motor and incorporated the use of a car alarm that would have received a signal from a transmitter to initiate the firing sequence.

The RCIED was identified as being viable but it did not receive an initiation signal from the remote transmitter.

The shrapnel that would have been fired from the device by the black powder was identified as lead fishing weights. The bulletin confirmed that the lead weights were coated in a ?green substance? later identified as an active ingredient in rat poison. The use of rat poison in suicide bombs by Palestinians has been documented in the past, as the chemical can act as an anticoagulant.

The pipe bomb was contained in a plywood box wrapped in T-shirts which were in turn wrapped with tape and placed inside a backpack, which was found on a bench along the Unity March route in downtown Spokane on the morning of Jan.17.

The threat analyses of the device indicated it contained a low level of sophistication, though the report did acknowledge ?the bomb maker possesses a greater degree of knowledge and skill than the typical pipe bomb builder.? Furthermore, the bomb was built using materials commonly available over the counter in the United States and used techniques ?published in open sources.?

The bulletin said the use of rat poison has been previously reported as being associated with suicide bombers in the Middle East, however it was not known whether the chemical would have been incinerated at the time the RCIED was detonated.

Frank Harrill, special agent in charge of the Spokane FBI field office, would not comment on the authenticity of the document.

RELATED DOCUMENT: Unclassified Intelligence Bulletin - MLK Day Bomb (PDF)