The military plans a mental evaluation to determine whether the Army psychiatrist charged with killing 13 people at Fort Hood knew his alleged actions were wrong and whether he's competent to stand trial, his civilian attorney said Tuesday.

Attorney John Galligan said he received notice Tuesday night from Maj. Nidal Hasan's captain that the military likely will issue a "mental responsibility exam" order Wednesday. The notice did not indicate when or where the exam, which is done by what the military calls a sanity board, will take place, Galligan said.

Hasan has been charged with 13 counts of premeditated murder in the Nov. 5 shooting spree on the Texas post, which left more than two dozen others wounded. Authorities have not said whether they will seek the death penalty.

"Given the magnitude and seriousness of the crimes alleged ... such alleged conduct makes me believe ... that the accused lacks mental responsibility and capacity," Capt. J. Huber wrote in the notice sent to Galligan.

Such an evaluation aims to ascertain whether a suspect had mental responsibility at the time of a crime, which means determining whether a mental illness prevented a suspect from knowing that what he was doing was wrong, according to military law. The exam also would determine if Hasan is competent to stand trial, Galligan said.

The board's determination could affect the charges, defense strategy and how the case proceeds, he said.

But Galligan said the exam is premature because Hasan remains in intensive care at a San Antonio military hospital, recovering from gunshot wounds that left him paralyzed. Military officials also have said Hasan could face other charges, Galligan said.

"They're acting prematurely and showing that this case is not going to go down the normal track," Galligan told The Associated Press from his office near Fort Hood, southwest of Fort Worth. "How and when and where they do the evaluation is problematic too."

Chris Haug, a Fort Hood spokesman, said Tuesday night that he had no information about a mental evaluation for Hasan. He declined further comment, citing the ongoing investigation.