(San Antonio, TX) -- The attorney for alleged Fort Hood shooter Nidal Hasan says his client may plead not guilty to killing 13 people at the Texas Army post on November 5th.

ABC News is reporting Hasan's civilian attorney, retired Army Colonel John Galligan, said it's possible an insanity defense will be used in the case. At the suspect's first court hearing on Saturday, Galligan said he learned his client could face additional charges.

Hasan, an Army psychiatrist, already is charged with 13 counts of premeditated murder in connection with the shooting rampage.

The hearing took place in his San Antonio hospital room, where Hasan is recovering from gunshot wounds received in the incident.

He is paralyzed from the chest down.

(Copyright 2009 by VERTEXNews/Newsroom Solutions)