Lt. Col. Kris Poppe, Hasan's lead court-appointed standby attorney, said he is willing to step in and be Hasan's defense lawyer. But he asked that his responsibilities as co-counsel be minimized if Hasan, who is representing himself at trial, continues to work toward being executed.
It is "clear his goal is to remove impediments or obstacles to the death penalty and is working toward a death penalty," Poppe told the judge overseeing the case at the Texas military base.
Hasan responded: "I object. That's a twist of the facts."
The judge, Col. Tara Osborn, then cleared the courtroom.
Hasan has chosen to act as his own attorney during the military trial at Fort Hood, though he has defense attorneys on standby if he needs them.
On Tuesday, he told jurors during a less than 2-minute opening statement that the evidence would "clearly show" he was the shooter, but that it would "only show one side." He also questioned only two of the first dozen witnesses, who included one soldier who was shot seven times during the November 2009 attack on the sprawling Army post.
Hasan is charged with 13 counts of premeditated murder and 32 counts of attempted premeditated murder. If convicted, he would face the death penalty.
Poppe said Hasan was acting as his own attorney in a way that, "we believe is repugnant to defense counsel and contrary to our professional obligations."
Hasan repeatedly asked the judge to allow him to explain why Poppe's claim was wrong, saying: "Your honor, Col. Poppe has made an assertion that is inaccurate. I'd like to clarify that."
Osborn paused for nearly half minute before asking that Hasan explain his argument in writing. He said he wouldn't do that.
Osborn then closed the courtroom to discuss the matter. No witnesses were called Wednesday.
Hasan, an American-born Muslim who was paralyzed after being shot by officers responding to the attack, said he was as a soldier who switched sides in what he described as a war between America and his Islamic faith. He then fell silent for most of the day.
Hasan wanted to plead guilty to murder and attempted murder, but military rules forbid guilty pleas in death penalty cases.
Hasan had also asked to argue that he carried out the shooting in "defense of others," namely members of the Taliban fighting in Afghanistan, but the judge denied that strategy. His defense strategy still remains unclear.
During Tuesday's testimony, he occasionally took notes on a legal pad. While two defense attorneys remained on stand-by, Hasan rarely turned to them for advice.
No American soldier has been executed since 1961, and military prosecutors showed that they would take no chance of fumbling details that could jeopardize any conviction down the line.
The long-delayed trial was years in the making after judges in the case had granted a series of delays. A fight over Hasan's beard, which violates military regulations, led to a stay shortly before his trial was expected to begin last year and eventual replacement of the judge.
The trial is playing out amid high security at Fort Hood, where armed guards stood in doorways and 15-foot stacks of shock-absorbing barriers obscured the view of the courthouse. Jurors were told to prepare for a trial that could take months, and Hasan, who is in a wheelchair, needs regular breaks.