A backpack bomb with the potential of killing or injuring dozens of people was found Monday along the route of a Martin Luther King Day “unity march” in downtown Spokane, Wash., authorities said today.
“It was a device that clearly was intended to harm or kill people,’’said Frank Harrill, a senior FBI agent and spokesman for the bureau’s Inland Northwest Joint Terrorism Task Force.
Harrill would not discuss the type of explosive or its construction, including whether the backpack contained an explosive shield intended to spray shrapnel toward potential victims. He also declined to say if the device was intended to be detonated remotely or by a timer.
“It had the potential to detonate during a unity march on the King Holiday, so, obviously it had political or social overtones,’’ Harrill said.
There was no threat made before the device was discovered by three construction workers about a block from the city’s Opera House and Convention Center where various speakers, including Spokane Mayor Mary Verner, spoke after the march.
No similar devices have been found and no group or individuals have claimed responsibility, Harrill said.
The device was rendered safe by a police bomb squad on a park bench where it was found after police rerouted 1,500 unity parade marchers around the site.
“We recovered a great deal of evidence,’’ Harrill said, declining to say whether fingerprints or DNA evidence may have been recovered.
Although a motive hasn’t been publicly identified, Harrill said the timing and placement of the potentially deadly bomb suggests possible ties to domestic terrorism or hate groups.
The investigation was assigned to the Inland Northwest Joint Terrorism Task Force, composed of various investigators from an assortment of federal, state and local agencies.
Those investigators worked through the night Monday but had made no arrests by late Tuesday. The same task force also continues investigating another improvised explosive device that was left last year, unexploded, outside the federal courthouse in downtown Spokane.
“We are not able at this time to link this device to any other similar device, but that certainly remains an area of intense focus,’’ Harrill said.
In the 1980s and 1990s, individuals with ties to extremist and hate groups were convicted of planting and detonating homemade pipe bombs at various locations in Spokane and nearby Coeur d’Alene and Hayden Lake, Idaho, which served as headquarters of the Aryan Nations.
The FBI released photographs of two T-shirts found in the backpack after it was disarmed Monday.
One of those T-shirts was from a cancer fund-raising event in 2010 in Stevens County, in northeastern Washington. Individuals linked to the earlier bombings in Eastern Washington and North Idaho had ties to militia and Christian Identity groups in Stevens County.
On July 27, 1996, a backpack bomb exploded near a park bench in Olympic Centennial Park in Atlanta, Ga., killing a woman and injuring 111 others. Eric Robert Rudolph, raised in a family with ties to Christian Identity, ultimately was arrested and convicted of being the Olympic Park bomber.