"While the Supreme Court has not articulated a general standard for the nature or quantum of evidence necessary to trigger a competency procedure, it has focused on three factors that should be considered: the existence of a history of irrational behavior, defendant's demeanor at trial, and a prior medical opinion."Lokos v. Capps, 625 F.2d 1258,1261-62 (5th Cir. 1980) (internal citations omitted): accord United States v. Moghaddam, 299 Fed. App'x 418, 420 (5th Cir. Nov. 17, 2008) (per curiam) (designated unpublished) (relying on same factors as in Lokos in post-conviction challenge to competency).