Federal marshals are reviewing security procedures after an inmate receiving treatment at a hospital overpowered a private guard, took her gun and set off a frenzied manhunt that included two carjackings.

U.S. Marshal for the Eastern District of Virginia Bobby Mathieson said Tuesday that the escape by 42-year-old Wossen Assaye from Inova Fairfax Hospital prompted questions about why two guards assigned to him were insufficient to prevent his escape.

He said he believes two people should be enough to guard a prisoner.

Assaye was charged earlier this month as the "Bicycle Bandit," accused of robbing a dozen banks in northern Virginia and sometimes fleeing on two wheels.

Authorities say he was in the hospital after attempting suicide at the jail.

He was loose for nine hours Tuesday before being re-arrested.