Manassas, Va. ? Sniper suspect John Allen Muhammad may have been exposed to nerve or chemical agents during his military service in the Persian Gulf War, his attorney told a judge Friday.

Jonathan Shapiro said after the court hearing that the defense had specific information that indicates possible exposure, but he declined to elaborate. “It’s not wild conjecture,” Shapiro said.

Muhammad is charged with capital murder in the Oct. 9 shooting of Harold Dean Meyers, 53, of Gaithersburg, Md., outside a gasoline station in Manassas. Muhammad has an October trial date.

His former companion, Lee Boyd Malvo, 18, is charged with capital murder in the Oct. 14 shooting of FBI analyst Linda Franklin, 47, outside a Home Depot store in Fairfax. Malvo faces trial Nov. 10.

Sniper suspect John Allen Muhammad's attorney says his client may have been exposed to nerve or chemical agents during his military service in the Persian Gulf War.

In all, the two are charged with shooting 19 people, killing 13 of them, last fall in Alabama, Georgia, Louisiana, Maryland, Virginia and Washington, D.C.

Shapiro mentioned the chemical exposure during a brief hearing in which he successfully argued for the appointment of a mitigation expert, who will look for evidence that might aid Muhammad if he is convicted.

Shapiro mentioned Muhammad’s service as a Gulf War veteran and “possible exposure to nerve agents and chemical weapons while he was there. There’s a whole lot about this man we need to investigate thoroughly.”

Shapiro said after the half-hour hearing that Muhammad, 42, served as an Army engineer during the 1991 war.