A federal grand jury has indicted a Stevens County man with purported ties to a neo-Nazi group on charges of attempting to detonate a rat-poison-laced bomb along the route of Spokane’s Martin Luther King Jr. Day parade in January.

Kevin William Harpham is scheduled to appear in U.S. District Court in Spokane on Wednesday to be arraigned on charges of attempting to use a weapon of mass destruction and one count of knowingly possessing an improvised explosive device. The weapon-of-mass-destruction charge carries a penalty of up to life in prison.

Harpham, 36, was arrested March 9 by an FBI Hostage Rescue Team near his home in the small, rural community of Addy, about 55 miles northwest of Spokane.

Harpham is expected to enter a plea of not guilty — a requirement at this stage because he faces a life prison sentence — and will be assigned a judge and trial date.

The two-page indictment provides no details of the investigation and gives no indication that others were involved.

First Assistant U.S. Attorney Tom Rice declined to comment on the indictment and said that the search warrants in the case, which would detail the investigation, will remain under court seal “”for the immediate future.””

Harpham is accused of leaving a backpack containing the potentially lethal bomb on a bench along the route of the Jan. 17 parade in downtown Spokane. The backpack was found by three city sanitation workers 40 minutes before the start of the parade.

A federal affidavit outlining the evidence has been sealed, but a source familiar with the investigation said authorities linked Harpham to purchases of bomb components, including a remote car starter and other electronics. The purchases were traced to various stores, and at least one purchase was made with a debit card, the source said.

In addition, DNA recovered in the backpack or on the bomb was linked to Harpham, the source said.

Harpham was a member of the neo-Nazi National Alliance in late 2004, according to Mark Potok, director of the Southern Poverty Law Center. Potok, whose Alabama-based office tracks hate groups in the United States, said it was not known when Harpham joined or whether he was still a member.

However, Erich Gliebe, chairman of the National Alliance, based in Hillsboro, W.Va., told The Spokesman-Review of Spokane that Harpham is not a member.

Harpham also posted his thoughts more than 1,000 times since 2004 on the Vanguard News Network, or VNN, a racist and anti-Semitic website, according to the Law Center. He also was a contributor to the white nationalist newspaper The Aryan Alternative, the Law Center said.

Harpham served in the Army and was stationed at Fort Lewis, now known as Joint Base Lewis-McChord, from June 1996 to February 1999 as a fire-support specialist in the 1st Battalion, 37th Field Artillery Regiment, according to a base spokesman.

Harpham’s father, Bill Harpham, told two Spokane television stations last week that his son may have had a hand in building the bomb, even if he didn’t plant it along the parade route. He said the son talked to hate groups on the Internet but was never compelled to act on those beliefs.

Bill Harpham said he was being cared for by his son when the backpack bomb was found Jan. 17, and that Kevin could not have driven the 160 miles to and from his home in Kettle Falls to plant the device in Spokane. He said he needs his son’s care as he recovers from a stroke suffered in November.

Kevin Harpham owns 10 acres of land north of Addy, a few miles south of his father’s home. His lawyers have said he was not married and had not been recently employed.