SPOKANE, Wash. (AP) — A man accused of trying to bomb a Martin Luther King Jr. Day parade in Spokane was an avid poster on a white supremacist Internet forum, where he referenced bomb-making and alluded to attacking anti-racist demonstrators, a national organization that tracks hate groups said Thursday.

The Southern Poverty Law Center said Kevin Harpham, 36, made more than 1,000 postings on the Vanguard News Network site, many of them under the pseudonym “Joe Snuffy.”

“I can’t wait till the day I snap,” said a 2006 message attributed to Harpham.

Harpham was arrested Wednesday after being charged with one count of attempting to use a weapon of mass destruction and one count of possessing an unregistered explosive in a case that raised concern in a region that was once a hotbed for hate groups. Three city workers discovered the backpack bomb on a bench just before the start of the Jan. 17 parade, and it was defused without incident.

A federal law enforcement official confirmed that investigators are aware of Internet postings attributed to Harpham and are reviewing those as they consider bringing additional charges under federal hate-crime laws. The official spoke on condition of anonymity because the case is ongoing.

Harpham’s lawyer, federal public defender Roger Peven, said he has heard about the Internet postings, but had not seen any of them. He said he would not be surprised if prosecutors altered the original charges, possibly to include hate-crime allegations.

“I would expect that what we see in the complaint is not necessarily what we will see in an indictment,” Peven said.

The authenticity of the Web postings could not be immediately confirmed, but two factors pointed to Harpham as their author. In one 2008 posting, someone wrote as “Kevin Harpham” seeking technical assistance in accessing his “Joe Snuffy” account.

The other factor, according to the Southern Poverty Law Center, was that in one post, well-known white supremacist Glenn Miller wished the account’s owner a happy birthday — on Harpham’s actual birthday, May 1.

The website’s administrator did not immediately return e-mails from The Associated Press seeking comment.

Harpham apparently contributed financially to Miller’s white nationalist newspaper, The Aryan Alternative, said Mark Potok of the Southern Poverty Law Center. In 2007, Miller wrote to Harpham on the Vanguard News Network, “You rank among the top 5-6 VNN’ers in total amount of money contributed. When (we) needed a boost, you were always among those who stepped up.”

In 2006, “Joe Snuffy” posted in response to video footage of anti-racists protesting white supremacists in Germany, saying it nearly made him snap. The post complained that the police cared only about the protesters and “turned their loaded guns on the neo-Nazis.”

“Videos like that bring me closer to it every time I watch them,” the post said. “Fear of death is the only thing stopping me and it is a fear that is hard to get over if you can relate to that.”

A 2010 writing attributed to Harpham mentioned that the mildly radioactive element thorium is useless for building bombs, and another post expressed his disappointment that the race-war novel “The Turner Diaries,” by the founder and leader of the white supremacist National Alliance, William Pierce, did not include plans for making a bomb.

Harpham was a member of the National Alliance in 2004, the Southern Poverty Law Center said.

Erich Gliebe, chairman of the National Alliance, based in Hillsboro, W.Va., told The Spokesman-Review newspaper of Spokane that Harpham is not a member of his organization, which he said believes all races are entitled to their own living spaces.

“We have a zero tolerance policy regarding illegal activity and anyone committing those acts – even hinting or joking — would not be welcome in our organization,” Gliebe said.

The FBI agent in charge of the agency’s Spokane office, Frank Harrill, said Thursday that bomb technicians’ decision to disable the explosive, rather than detonate it, helped lead to Harpham’s arrest. Investigators were able to obtain evidence from bomb itself, he said.

He declined to specify what type of evidence was taken from the bomb.

“The explosive disposal unit here in Spokane displayed an extraordinary amount of expertise and courage that enabled us to process a complete device,” Harrill said.

Copyright 2011 The Associated Press.