Prosecutors are seeking a competency hearing and a full psychological screening of Oscar Ortega-Hernandez. He has been charged with trying to kill Obama when he opened fire on the White House with a semi-automatic assault rifle.
An initial screening ordered by a federal magistrate on November 21 concluded that Ortega-Hernandez was competent, according to a court filing.
"The government notes that it was based only on a 50-minute screening and submits a full psychiatric or psychological screening ... is warranted, given the serious nature of the criminal charges pending against the defendant and the likelihood that mental health issues may arise in the course of these proceedings," the prosecutors said in a motion.
U.S. Magistrate Judge Alan Kay agreed to delay a detention hearing until December 12 and asked prosecutors to provide "more substance" to their motion.
Ortega-Hernandez, 21, of Idaho Falls, Idaho, was ordered held pending that hearing.
Witnesses interviewed by authorities said Ortega-Hernandez had called the president the "devil" and "anti-Christ."
His abandoned car was found blocks from the White House after the Friday night shooting. He was arrested at a hotel near Indiana, Pennsylvania, the following Wednesday.
If convicted, Ortega-Hernandez faces up to life in prison.