They knew the Delano house far too well. It was where Christian Philip Oberender, then 14 years old, had murdered his mother in a shotgun ambush in the family rec room in 1995.

Now, 18 years later, Carver County Sheriff Jim Olson was sending his deputies back to the home where Oberender still lives. Just two days earlier, Olson had scanned the day's shift reports and froze when he tripped over Oberender's name. A scan of a Facebook page then showed firearms spread out like a child's trophies on a bed inside the home, along with notes about the Newtown, Conn., gunman who shot 20 children to death.