OAK CREEK, Wis. (AP) - Wade Michael Page played in white supremacist heavy metal bands and posted frequent comments on Internet forums for skinheads, repeatedly exhorting members to act more decisively to support their cause.

"If you are wanting to meet people, get involved and become active," he wrote last year. "Stop hiding behind the computer or making excuses."

A day after Page strode into a Sikh temple with a 9mm handgun and multiple magazines of ammunition, authorities were trying to determine if the 40-year-old Army veteran was taking his own advice when he opened fire on total strangers in a house of worship.

Detectives cautioned they might never know for sure. But the picture of Page that began to develop Monday - found in dark corners of the Internet, in records from a dodgy Army career and throughout a life lived on the margins - suggested he was a white supremacist who wanted to see his beliefs advanced with action.

Page, who was shot to death by police, described himself as a member of the "Hammerskins Nation," a skinhead group rooted in Texas that has branches in Australia and Canada, according to the SITE Monitoring Service, a Maryland-based private intelligence firm that searches the Internet for extremist activity.

Between March 2010 and the middle of this year, Page posted 250 messages on one skinhead site and appeared eager to recruit others. In March 2011, he advertised for a "family friendly" barbecue in North Carolina, imploring others to attend.

In November, Page challenged a poster who indicated he would leave the United States if Herman Cain was elected president.

"Stand and fight, don't run," he implored.

In an April message, Page said: "Passive submission is indirect support to the oppressors. Stand up for yourself and live the 14 words," a reference to a common white supremacists mantra.

The bald, heavily tattooed bassist trained in psychological warfare before he was demoted and discharged more than a decade ago. After leaving the military, he became active in the obscure underworld of white supremacist music, playing in bands with names such as Definite Hate and End Apathy.

Still, Oak Creek Police Chief John Edwards cautioned Monday that investigators might never know for certain what motivated the attack on the Sikh Temple of Wisconsin in suburban Milwaukee. So far, no hate-filled manifesto has emerged, nor any angry blog or ranting Facebook entries.

"We have a lot of information to decipher, to put it all together before we can positively tell you what that motive is - if we can determine that," Edwards said.

Mark Potok, a senior fellow at the Southern Poverty Law Center, a nonprofit civil rights organization in Montgomery, Ala., described Page as a "frustrated neo-Nazi" whose bands' sinister-sounding names seemed to "reflect what he went out and actually did."

Their lyrics talked about genocide against Jews and other minorities.

In a 2010 interview, Page told a white supremacist website that he became active in white-power music in 2000, when he left his native Colorado and started the band End Apathy in 2005 in Nashville, N.C.

Across several states, fragments of Page's life emerged Monday in public records and interviews.

He joined the military in Milwaukee in 1992 and was a repairman for the Hawk missile system before switching jobs to become an Army psychological operations specialist in a battalion at Fort Bragg, N.C.

In "psy-ops," Page would have trained to host public meetings between locals and American forces, use leaflet campaigns in a conflict zone or use loudspeakers to communicate with enemy soldiers.

He never deployed overseas in that role, Army spokesman George Wright said.

Page was demoted in June 1998 for getting drunk on duty and going AWOL, two defense officials said, speaking on condition of anonymity because they were not authorized to release information about the gunman.

Page also received extra duty and was fined. The defense officials said they had no other details about the incident, such as how long Page was gone or whether he turned himself in. He was discharged later that same year.

Page bought a brick ranch house outside Fayetteville, N.C., in 2007 with help from a Veterans Affairs mortgage. But on Monday the home was boarded up with knee-high weeds in the yard. A notice taped to the front indicated the home was in foreclosure and had been sold to a bank in January.

Before buying the home, Page lived with Army soldier Darren Shearlock, his wife and young children in a doublewide trailer in a rural community near Fort Bragg, records show.

Shearlock, dressed in his military fatigues, declined to comment about Page or the shooting when approached Monday by The Associated Press.

Page's former stepmother said she was devastated to learn of the bloodshed.

"He was a precious little boy, and that's what my mind keeps going back to," said Laura Page, of Denver, who was divorced from Page's father around 2001.

In Wisconsin, Page responded to a recent online ad seeking a roommate in Cudahy, a small city outside Milwaukee.

He rented a room in Kurt Weins' house in June, telling Weins he had recently broken up with his girlfriend and needed a place to stay.

Weins said Page stayed in that room all the time, declining invitations to watch TV with him. Page explained that he wanted to bring some belongings out of storage, so he rented an apartment several weeks later in a duplex owned by Weins across the street.

"We talked, but it was really about nothing," Weins said. "He seemed pretty calm. He didn't seem like the type to raise his voice."

After the FBI searched the apartment in the duplex, Weins returned and found only a computer desk, chair and an inflatable mattress.

Suburban Milwaukee police had no contact with Page before Sunday, and his record gave no indication he was capable of such intense violence.

The FBI was leading the investigation because the shooting was considered domestic terrorism. The agency said it had no reason to believe anyone other than Page was involved.

Page entered the temple as several dozen people prepared for Sunday services. He opened fire without saying a word.

The president of the temple died defending the house of worship he founded.

Satwant Singh Kaleka, 65, managed to find a simple butter knife in the temple and attempted to stab the gunman before being shot twice, his son said Monday.

Amardeep Singh Kaleka said FBI agents hugged him, shook his hand and told him his father was a hero.

"Whatever time he spent in that struggle gave the women time to get cover" in the kitchen, Kaleka said.

With their turbans and long beards, Sikhs are often mistaken for Muslims or Arabs, and have inadvertently become targets of anti-Muslim bias in the United States.

Federal officials said the gun used in the attack had been legally purchased. Page had been licensed to own weapons since at least 2008, when he paid $5 each for five pistol-purchase permits in North Carolina.

The six dead ranged in age from 39 to 84 years old. Three people were critically wounded, including a police officer.

Online records show Page had a brief criminal history in other states, including pleading guilty to misdemeanor criminal mischief after a 1994 arrest in El Paso, Texas, for getting drunk and kicking holes in the wall of a bar. He received six months' probation.

Page also pleaded guilty to driving under the influence in Colorado in 1999 but never completed a sentence that included alcohol treatment, records show.

He was arrested on suspicion of drunken driving again in 2010 in North Carolina after running his car off the side of a highway. The case was dropped a year later for lack of evidence, according to court records.