WASHINGTON (AP) — A man accused of trying to kill President Barack Obama by firing several shots at the White House from long range must remain in custody to protect the public and the president, a federal judge said Monday.

U.S. Magistrate Judge John Facciola’s order that Oscar Ramiro Ortega-Hernandez be detained without bond was not unexpected given the seriousness of the charge Ortega faces — attempting to assassinate the president. It followed a two-hour hearing in which Ortega’s public defender aggressively questioned an FBI agent about the strength of the government’s case and apparent contradictions in witness statements.

Obama and his wife, Michelle, were out of town on the evening of Nov. 11 when authorities say Ortega used an assault rifle with an attached scope to fire up to a dozen shots at the White House from his vehicle. Two bullets and one bullet fragment were recovered from the grounds of executive mansion, including one that was stopped by bulletproof glass. Investigators found five bullet impact points on the south side of the building on or above the second story, where the first family resides.

Friends and associates told investigators that Ortega — a 21-year-old Idaho Falls, Idaho native — has long been obsessed with Obama and referred to the president as the antichrist. Ortega, who has shoulder-length dark hair and a long beard, called himself “the modern-day Jesus Christ” and told at least one person he intended to kill the president, authorities allege.

Ortega’s attorney, David Bos, argued that prosecutors had failed to establish that Ortega was present when the shots were fired or that the president was the target of the attack.

“We believe this to be an extraordinarily weak government case,” Bos said.

Prosecutors have raised concerns about Ortega’s mental state, although an initial psychiatric screening found him competent to stand trial.

“The defendant is a particularly dangerous individual,” Facciola said, adding that he could not set any conditions for release that would ensure public safety.

Ortega will continue to be held in an undisclosed federal detention facility. He faces a possible life sentence if convicted, and he would be a flight risk if released, Facciola said.

He noted that Ortega’s departure from the Washington area after the shooting was “a remarkable one, on a freight train.”

Prosecutors introduced a photo of Ortega’s head popping out of an empty rail car that was snapped by a retired FBI photographer who takes pictures of trains as a hobby. The picture was taken three days after the shooting near Shenandoah Junction, W.Va., and the train had originated in Washington. Ortega was arrested on Nov. 16 at a hotel in Indiana, Pa., where he had stayed with friends before the shooting.

Two witnesses told investigators that they heard gunshots or popping sounds and saw a dark-colored sedan on Constitution Avenue south of the White House on the evening of Nov. 11. But neither of them identified Ortega as the shooter, FBI Special Agent Michael Pinto said under cross-examination.

A jogger who flagged down police immediately after the shooting gave “a vastly different version of events,” Bos said, telling investigators that the shooting involved two vehicles, including a yellow truck.

Assistant U.S. Attorney John Borchert said the government had substantial evidence linking Ortega to the shooting. He also said there’s no evidence to substantiate Ortega’s claim to investigators that he was carjacked on the afternoon before the attack.

“It’s his car. It’s his gun. It’s his bullets,” Borchert said. “There’s a compelling case of identification here.”

Copyright 2011 The Associated Press.