WASHINGTON -- Federal investigators had “looked at” Sikh temple gunman Wade Michael Page more than once because of his associations with right-wing extremists and the possibility that he was providing funding to a domestic terrorist group, but law enforcement officials at the time determined there was not enough evidence of a crime to open an investigation, a senior U.S. law enforcement official said.

The official, who spoke on condition of anonymity because he was not authorized to speak to the media, would not say Monday which law enforcement agency had considered investigating Page, or when.

Before his rampage Sunday at a Sikh temple in Oak Creek, Wis., that left him and six others dead and three critically wounded, Page was known to civil rights groups as a member of two racist skinhead bands – End Apathy and Definite Hate. He was also believed to have been a low-level member of a national white supremacist group called the Hammerskins.

PHOTOS: Gunman opens fire at Sikh temple

Racist skinhead bands and record labels have been known by law enforcement to raise money for extremist groups in the U.S.

Both the Anti-Defamation League and the Southern Poverty Law Center had tracked Page for several years. The nonprofit organizations collect publicly available information on hate groups from Web forums, pamphlets and other sources.

But the FBI is prohibited under federal law from collecting information on U.S. citizens not suspected of....REST OF IT