OAK CREEK, Wis. >> Before he strode into a Sikh temple with a 9mm handgun and multiple magazines of ammunition, Wade Michael Page played in white supremacist heavy metal bands with names such as Definite Hate and End Apathy.

The bald, heavily tattooed bassist was a 40-year-old Army veteran who trained in psychological warfare before he was demoted and discharged more than a decade ago.

A day after he killed six worshippers at the suburban Milwaukee temple, fragments of Page’s life emerged in public records and interviews. But his motive was still largely a mystery. So far, no hate-filled manifesto has emerged, nor any angry blog or ranting Facebook entries to explain the attack.

Page, who was shot to death by police, joined the Army in 1992 and was discharged in 1998. He was described Monday by the Southern Poverty Law Center as a “frustrated neo-Nazi” who had long been active in the obscure underworld of white supremacist music.

Page wrote frequently on white supremacist websites, describing himself as a member of the “Hammerskins Nation,” a skinhead group rooted in Texas that has offshoots in Australia and Canada, according to the SITE Monitoring Service, a Maryland-based private intelligence firm that searches the Internet for terrorist and other extremist activity.

In online forums, Page promoted his music while interacting with other skinheads. He posted 250 messages on one site between March 2010 and the middle of this year, and appeared eager to recruit others. In March 2011, he advertised for a “family friendly” barbeque in North Carolina, extolling those online to attend.

“If you are wanting to meet people, get involved and become active, then you really need to attend,” he wrote, according to SITE. “Stop hiding behind the computer or making excuses.”