The man supected of shooting at the White House last Friday had become obsessed with President Barack Obama, officials have told US media.It is thought Oscar Ortega-Hernandez, 21, believed God had given him a personal mission to attack the White House, said law enforcement sources.A US Park Police bulletin said he was \"unstable with violent tendencies\".Mr Ortega is scheduled to appear in court in Pittsburgh, Pennsylvania, on Thursday afternoon.He was arrested in that state on Wednesday after authorities were tipped by someone who recognised him.Gunfire was heard between the White House and the Washington Monument on Friday evening.Police later discovered an abandoned car with an assault rifle inside.Two bullets were found on the south side of the the executive mansion on Tuesday, the part of the building where the president\'s bedroom is located.One bullet broke a \"historic\" outside pane of glass but was stopped by a protective inner panel of ballistic glass. The second bullet hit the exterior of the building.The president and first lady were not in Washington at the time, but it is not known if their two daughters, Sasha and Malia, were at home.Secret Service officials told reporters the bullets had not yet been conclusively linked to Friday\'s gunfire.Originally from the US state of Idaho, Mr Ortega was reported missing by his family on 31 October. It is thought that he had been living in the Washington DC area.He has a history of arrests in Texas, Utah and Idaho but police say he has not been linked with any radical organisations.