(Medford, OR)  --  Federal authorities say a Medford man has pleaded guilty to making online threats to kill President Obama and shoot FBI agents.  Authorities say Roos was arrested in April after a .45-caliber pistol was recovered from a vehicle belonging to the defendant, and a number of other weapons and hundreds of rounds of ammo were recovered from his home.  The FBI says four pipe bombs were also found in Roos's living room.  Roos could face up to ten years in prison.