Page was involved in the world of White Supremacist heavy metal, playing at one point with a skinhead group known as the Hammerskins. That is what that caught the attention of the Anti-Defamation League (ADL) about seven years ago.
"We noticed that he was involved in this band for a while and we began gathering pictures and lyrics," Lonnie Nasatir, Anti-Defamation League, said.
Largely through the internet, the ADL and other civil rights organizations that monitor hate groups can legally build files on people like Page that law enforcement is precluded from doing. That information usually isn't formally shared with police or the FBI unless there is a specific threat or specific words to incite violence.
"When we think it crosses that legal threshold then the FBI feels more comfortable in opening a file for an investigation," Nasatir said.
In the case of Wade Page, there were racist affiliations, white power tattoos and heavy metal lyrics to supremacist causes -- but no specific threats that might have prompted the FBI to open a case file. Beyond some misdemeanors and drunk driving convictions, Page had no history of violent crime. He appears to have left no manifesto, so the specifics of motive may depend on whether he told anyone of his intent.
"Things that he sent to a friend, said to a friend. We may find out more. that's what the FBI and local are doing in next couple days to get a sense of what's on his mind," Nasatir said.
Page's girlfriend, identified as Misty Cook, is in FBI custody. She and Page were living together until recently, when she reportedly told neighbors, "Wade just fell off the face of the earth."
Cook is also affiliated with a white supremacist group, according to ADL. She was taken into custody because she is a convicted felon who was in possession of a handgun, law enforcement officials said.