"The house itself is kind of shrouded, it's covered up ... like cold, cold dark unpleasant. ... I always felt unwelcome, always, like I shouldn't be there," Osler said.
Loughner's parents, Randy and Amy Loughner, did not attend their son's arraignment. Instead, the devastated parents issued a statement Tuesday, saying they "don't understand" what prompted their son to allegedly go on a "heinous" shooting rampage.
"This is a very difficult time for us. We ask the media to respect our privacy," according to the statement. "There are no words that can possibly express how we feel. We wish that there were, so we could make you feel better. We don't understand why this happened.
"It may not make any difference, but we wish that we could change the heinous events of Saturday. We care very deeply about the victims and their families. We are so very sorry for their loss."
It was the first word from Loughner's family since the carnage on Saturday.
The Loughners' note of confusion and contrition contrasted with a hateful scribble that was found in the Loughner home that simply read "Die bitch," a sheriff's official told The Associated Press. Other notes in the safe included "I planned ahead," "My assassination" and the name "Giffords."
Loughner's parents have sealed themselves in their suburban Tucson home since Saturday's shooting, blocking access to the front door with a piece of wood to presumably keep people off their property.
Osler pointed to an online documentary series called "Zeitgeist" as a possible influence on the man.
The series rails on currency-based economics.
"I really think that this 'Zeitgeist' documentary had a profound impact on Jared's mindset and how he viewed that world that he lives in," Osler said.
Osler also said that Loughner's favorite quote was "Out of chaos breathes creation."
Loughner ended his friendship with Osler through a text message two years ago, writing to him, "I don't want to be friends with you anymore."
"I forgot about Jared. I stopped thinking about this kid because thinking about him wasn't something I wanted to do," Osler said.
As Osler comes to terms with Loughner's descent, family members and supporters of the victims in the shooting will gather for a memorial today that Obama will lead.
The president worked overnight tinkering with the speech that his staff has been working on for days, sources told ABC News.
The speech is not expected to be political but rather about lifting the nation's spirits up, sources said.
Two church services were held for the victims Tuesday night.
Several hundred mourners filled a Tucson Catholic church for a public Mass. As people filed in, nine young girls sang "Amazing Grace."
The youngest victim of the attack, 9-year-old Christina-Taylor Green, was a member of the choir that sang.
"I know she is singing with us tonight," Tucson Bishop Gerald Kicanas told The Associated Press.
Today, Ben Heilman, the husband of the woman who took Christina to the political event that turned tragic, described Christina's relationship with his wife as a natural match.
"Christina is a very bright young girl who seemed to have a special propensity for engaging with adults, and my wife is a very playful older woman who had propensity for engaging with younger kids," Heilman said.