(CBS News) OAK CREEK, Wis. - Investigators are looking into possible white supremacist links to the gunman who killed six people and wounded three at a Sikh temple outside Milwaukee before being killed in a shootout with police.

Federal authorities say they'd come across Wade Michael Page, 40, before. And he had a criminal record, police say.

But his stepmother says the man being described is nothing like the person she remembers.

According to the Southern Poverty Law Center, Page was a member of two skinhead bands (video), including one called Definite Hate.

In a 2007 performance in South Carolina, the group played under a giant swastika flag emblazoned with the face of Adolph Hitler.

"We are looking at ties to white supremacist groups, of course," the FBI special agent in charge, Teresa Carlson, said at a news conference.

In a 2010 interview, Page, a U.S. Army veteran, said he started his other band, End Apathy, because, "the value of human life has been degraded by being submissive to tyranny and hypocrisy that we are subjugated to."

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