The police found a map of Camp David marked with a presidential motorcade route inside the Bethesda, Md, home of the teenager at the centre of a bomb-making probe, along with a document that appears to describe how to kill someone at a distance of 200 meters, a prosecutor said on Tuesday at a court hearing.

Collin McKenzie-Gude, 18, also had two forms of fake identification: one holding him out to be a CIA employee and the other in the name of a federal contractor — purporting to be protected by the Geneva Conventions — authorities said. He was arrested on July 30.

The investigation has expanded to include officials from the CIA, FBI and Secret Service, prosecutors said. McKenzie-Gude, who is in the Montgomery County jail, faces charges that include weapons violations, possession of explosives and attempted carjacking.

McKenzie-Gude was considered a fine student at St John’s College High, a private school in Washington DC. His father, Joseph Gude, 62, a retired Air Force captain who served in Vietnam and now works for the Treasury Department, also was charged in the case, accused of buying guns for his son.

A 18-year-old St John’s student was charged as a juvenile in connection with the case. Until recently, the student worked as an intern at a Montgomery County police district station, where authorities said he stole police letterhead stationery that was used to obtain items restricted to law enforcement personnel.

A former teacher of the two remembered them as “quiet, good-natured students.” “They were St John’s kids,” said Matt Feldman, who now teaches at another private school. “There was nothing dark about them.”

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