Therin Gartrell, 28, was arrested Sunday, just before the Democratic National Convention in Denver. Authorities said he was pulled over in the suburb of Aurora in a rented truck that contained rifles, a bulletproof vest, wigs and fake IDs, and that Gartrell and two other men had talked about killing Obama.

The U.S. attorney's office later said the men were drug users who made racist threats but had no firm assassination plot and no ability to carry one out. No one has been charged in relation to the alleged threats.

Aurora police say Gartrell had been on crutches when they arrested him. Handcuffed to his crutches in court Thursday, he spoke little and did not enter a plea.

Public defender Ed Harris was appointed to represent him. Harris was not present and did not immediately respond to a telephone message seeking comment.

Arapahoe County prosecutors had planned to charge Gartrell Thursday with state drug and weapons violations, but that was put on hold without explanation.

U.S. attorney's spokesman Jeff Dorschner said it was "best from a coordination standpoint" if the cases against Gartrell and the two other men were in federal court.

State prosecutors sometimes defer to their federal counterparts if a suspect can get a stiffer sentence in federal court.

A federal conviction for methamphetamine possession carries a prison term of up to two years with no time off for good behavior. Penalties under the state charges were not immediately available.