Authorities have conducted more than 100 interviews with people around the country and issued some 180 subpoenas, but are still seeking a better understanding about Wade Michael Page's motives for entering the Sikh Temple in Oak Creek and opening fire.
Officials also revealed in a Wednesday news conference that Page died of a self-inflicted gunshot to the head after he was shot by an Oak Creek police officer outside the temple Sunday morning.
The investigation into Page has spanned the country, as the 40-year-old "moved around a lot," FBI special agent in charge Teresa Carlson said. His reasons for moving to the Milwaukee area are believed to center around a girlfriend named Misty Cook.
The FBI has talked extensively with Cook since Sunday, Carlson said, but officials are confident she is not connected to the killings.
Cook was in custody briefly for being a felon in possession of a firearm, but she has not been charged, U.S. Attorney James Santelle said.
The FBI had 101 leads in the Sikh Temple killings as of 8 a.m. Wednesday and have worked around the clock on the case, Carlson said. Authorities are continuing to gather evidence at the Sikh Temple, with many rooms and a total of 16,000 square feet needing to be "meticulously searched," she said. More than 100 items have been recovered from the parking lot alone.
Authorities are also reviewing records from Page's phone and video from surrounding buildings and state Department of Transportation cameras. They have searched Page's residences and a space at one of his former employers.
Carlson said video cameras were not turned on at the temple at the time of the shootings.
The shot fired by an Oak Creek police officer was captured on a squad car video, however.
"I've seen the video — it is an amazing shot," Carlson said.
"Subsequent to that wound, it appears that Page died from a self-inflicted gunshot wound to the head."
Police Chief John Edwards said they do not want to identify the officer who shot Page because of possible retaliation by white supremacy groups, as well as the ongoing investigation.
He is not aware of any specific threat against the officer, but said the department always prepares for such a scenario.
"You always think about what-ifs," Edwards said. "If you just do 'what do we know,' you're going to get hit with something you didn't do a 'what-if' on."
Edwards said he was confident that Oak Creek and its residents are safe.
"What we know about what happened (is) there was a lone shooter," Edwards said.
"My community is safe. There's nobody else out there."