The chef of police sais TWO doors were chained. I believe that statement was made in the 7:30 news conference.
MSNBC says -
They found a cell phone near the dead shooter and they thought the cell phone belonged to the dead shooter. Now they believe the cell phone belonged to an Asian guy who arrived in August 2006 on a student visa, not the shooter.
They believe the shooter was in the US legally on a permanent visa so it would be legal for him to purchase guns in the USA.