After spending several days trying to extract data from Adam Lanza's damaged hard drive, investigators say that they've come up short. It wasn't for lack of trying, either. Connecticut State Police joined forces with the FBI in an attempt to recover the data but found no clues as to why the troubled 20-year-old stormed into Sandy Hook Elementary School and gunned down 20 first graders and six adults before killing himself. Lanza may have wanted it that way, since he destroyed the hard drive before leaving for the school. Before recovery efforts started on the hard drive, sources said that it "appeared to have been badly damaged with a hammer or screwdriver." On Monday, one investigator floated what may seem an obvious hypothesis, "He was eliminating [investigators'] ability to figure out what websites he had gone to or who he might have been communicating with."

This leaves police in a difficult position. Days after the event the people of Newtown and beyond are struggling to comprehend what would have motivated Lanza to commit such an unthinkable act. Was he talking to other potentially dangerous people online? Did he have a manifesto, some purpose or mission he thought that he was carrying out? What has happened recently in Lanza's life that could've set him off? For now, we don't know the answers to any of these questions, and we may never know. All that police can do is start asking them to people of the already shattered and traumatized Newtown, including the children that were in Sandy Hook. This won't be easy, as Connecticut State Police spokesman Lt. J. Paul Vance explained on Monday. "It's a very, very tender, tender issue," he said.

We do know that Lanza played violent video games. And he played them often. However, it's very difficult to say what kind of impact these video games might've had on his violent actions. A recent ten-country study showed that there's little correlation between violent video games and gun murders — though there are always exceptions. And as far as gun violence is concerned, America is clearly the exception to many trends worldwide.

Whatever Adam Lanza's reasons for going to Sandy Hook that day may have been, it's pretty clear now that we'll never know much why this tragedy happened from his video-game habits or his hard drive history. As President Obama said in his address at the Newtown vigil on Sunday, though, not knowing why is no excuse for not doing something to prevent this from happening again. "We will be told that the causes of such violence are complex, and that is true," said the president. "No single law, no set of laws can eliminate evil from the world or prevent every senseless act of violence in our society, but that can't be an excuse for inaction."