Updated at 2:38 p.m. ET
(CBS/AP) The FBI announced Wednesday that Wade Michael Page, the gunman in Sunday's shooting rampage at a Wisconsin Sikh temple, apparently died from a self-inflicted gunshot wound to the head after being shot in the stomach by a police officer responding to the scene.
Officials said they are still trying to determine a motive for the attack, which left seven people dead, including Page.
FBI Special Agent Teresa Carlson, who's in charge of the bureau's Milwaukee office, told reporters at a morning news conference that video footage from the shooting showed that Page apparently shot himself.
Previously, Oak Creek Police Officer Sam Lenda was credited with downing Page. Lenda was the second officer who responded to the scene. Carlson said Lenda shot Page in the stomach.
"It is an amazing shot and thank goodness," Carlson said.
The first responding officer, Oak Creek Police Lt. Brian Murphy, was shot nine times but survived the shooting. Oak Creek Police Chief John Edwards said at the news conference that Murphy has started walking around again.
Carlson said the bureau had received 101 leads "worldwide" during its investigation but reaffirmed that no one else other than Page has been connected to the shooting.
Carlson also provided more details into the arrest of Page's ex-girlfriend, 31-year-old nursing student Misty Cook. Cook was arrested Sunday after South Milwaukee police officers observed a weapon in her home during an interview for the Page investigation, Carlson said.
Cook was arrested on a charge of being a felon in possession of a firearm. Milwaukee County sheriff's spokeswoman Fran McLaughlin said the 31-year-old Cook also went by Brenda Cook. Online court records show Brenda Cook pleaded no contest in 2005 to a felony charge of fleeing an officer. Carlson said Misty Cook wasn't connected to the Sikh temple shooting and was cooperative.
Carlson said federal officials had not opened any investigation into Page before the shooting. She said investigators were interviewing dozens of people who have known Page as they worked to determine for a possible motive.
"We just want to get to the bottom of what motivated him to do it," said Amardeep Singh, an executive with the New York-based Sikh Coalition. "It's important to acknowledge why they lost their lives."
The 40-year-old Army veteran strode into the Sikh Temple of Wisconsin shortly before Sunday services and opened fire with a 9 mm pistol. The dead included temple President Satwant Singh Kaleka, who was shot as he tried to fend off the shooter with a ceremonial knife.
The fragments of Page's past that have emerged suggest he lived a somewhat troubled life.
A native of Littleton, Colo., he had a record of minor alcohol-related crimes in Texas, Colorado and North Carolina. He was demoted during a stint in the Army for getting drunk on duty and going AWOL before he was discharged in 1998. Page eventually moved to Wisconsin, living in South Milwaukee with Cook and working third-shift at a brazing factory in Cudahy, another Milwaukee suburb.
Neighbors said the couple broke up this past spring. Page moved into a Cudahy duplex in mid-July and quit showing up for work around the same time. A few days after he moved into the duplex, he visited a West Allis gun shop and, after clearing background checks, bought the gun he used in the shooting.
The Southern Poverty Law Center has described Page as a "frustrated neo-Nazi" who participated in the white-power music scene, playing in bands called Definite Hate and End Apathy.
Rajwant Singh, chairman of the Sikh Council on Religion and Education, said even though Page is dead, other white-supremacy and neo-Nazi groups could harbor similar intentions.
"Our concern is, how do we tackle these hate groups operating underground or in darkness?" he said.
The FBI has classified the incident as domestic terrorism, a violent act for social or political gain.
Now investigators face two tasks: determining what drove Page over the edge and whether anyone nudged him along the way.
Investigators probably will collect all the bullets and fragments from the temple and the victims' bodies to confirm that they came from Page's gun. Detectives also will pore over witness statements to make absolutely certain he was the only shooter, said Joe LeFevre, chairman of the forensic science department at Fox Valley Technical College in Appleton.
Authorities will interview Page's family, friends and associates. Agents spent Monday morning doing a door-to-door sweep on his street, chatting with neighbors on their front porches and in their backyards.
If agents seized a computer from his apartment, they likely will review the websites he visited and any writings he posted. If they recovered a cellphone, they will use it to follow his recent movements as the device shifted from one cell tower to the next.
"It's like any crime," said Jack Ryan, a Rhode Island attorney who trains police around the country. "You focus on their recent tracks. You focus on friends, acquaintances. He had to get ready for this plot somewhere."
If detectives determine Page simply held a personal grudge, the Sikhs and the rest of the public will have an answer. If investigators conclude he was motivated by racist ideology, that might lead police to accomplices, help collect intelligence on white supremacist groups and prevent future attacks.
No matter how thorough the investigation, the final conclusions are bound to leave victims with many of the same anguish-filled questions.
"Whatever the answer is, we can be reasonably sure it won't be an answer many people would say makes sense to them," said University of Wisconsin-Madison law professor Michael Scott, who is writing a guidebook for police on hate crimes.
"We'd like to have some peek into that twisted mind. But in the end, it's still a peek into a twisted mind that doesn't tell us anything we didn't already know about human nature."