But the two men who authorities say are responsible for the string of shootings that terrified the Washington, D.C., area were scheduled for a reunion of sorts as Malvo was to appear as a witness at Muhammad's pretrial hearing Wednesday.
Malvo's attorney, Craig Cooley, said prosecutors are aiming to determine whether Malvo will testify in Muhammad's trial by calling him to the stand. Cooley said his client will invoke his Fifth Amendment right against self-incrimination to remain silent.
Lt. Tyler Corey, a spokesman for the Fairfax County jail, confirmed that Prince William County authorities picked up Malvo Tuesday at the Fairfax jail in advance of the hearing in Manassas.
Peter Greenspun, Muhammad's lawyer, said Malvo was called as a witness regarding a motion that is under court seal, and said he could not comment further. He said he did not subpoena Malvo.
Prince William County Commonwealth's Attorney Paul Ebert could not be reached for comment Tuesday evening.
According to Cooley, legal ethics do not allow prosecutors to put a witness in front of a jury if they have a strong expectation the witness will invoke his constitutional right to avoid self-incrimination, so they deal with the issue in a pretrial hearing.
Cooley said he expects Muhammad will similarly be called as a witness at a pretrial hearing for Malvo.
Two other matters are scheduled for argument at Wednesday's hearing. One motion seeks to suppress statements by Muhammad to investigators following his Oct. 24 arrest. Defense lawyers argue that police did not inform Muhammad of his right to remain silent in a timely manner.
Lawyers for Malvo have made similar complaints about statements by their client. Last month, a judge ruled to allow the testimony of two prison guards who say Malvo bragged to them about committing several of the shootings.
A second motion seeks to bar the death penalty on one of two capital-murder counts levied against Muhammad. Defense lawyers argue that an antiterrorism statute under which Muhammad is charged is written in such a manner that the maximum penalty permitted should be life in prison.
Greenspun said Malvo has not been called as a witness for either motion.
Muhammad, 42, and Malvo, 18, have been charged with 13 shootings, including 10 deaths, over a three-week span in October in Virginia, Maryland, and Washington, D.C. They are also suspected or charged with shootings in Georgia, Alabama, Louisiana, Arizona and Washington state.
Muhammad's trial is scheduled Oct. 14 for the slaying of Dean H. Meyers, 53, at a gas station.
Malvo goes on trial Nov. 10 for the shooting death of FBI analyst Linda Franklin at a Home Depot store in Falls Church.