In this courtroom sketch, Staff Sgt. Michael Davis, a victim of the Fort Hood shootings, testifies during the trial of Maj. Nidal Hasan, Thursday, Aug. 8, 2013, in Fort Hood, Texas. Hasan was allowed to continue representing himself on Thursday after the judge barred his standby attorneys from taking over, despite their claims that the Army psychiatrist was trying to secure his own death sentence. In this courtroom sketch, Maj. Nidal Hasan, second from right, sits with his standby defense attorneys Maj. Joseph Marcee, left, and Lt. Col. Kris Poppe, second from left, as presiding judge Col. Tara Osborn looks on, during Hasan's trial Thursday, Aug. 8, 2013, in Fort Hood, Texas. FORT HOOD, Texas (AP) - The soldier knew she had to decide quickly who she could save, so she grabbed a black marker and wrote a "D" on the foreheads of those she couldn't. To people lingering over the dead amid the chaos of the 2009 shooting rampage at Fort Hood, she shouted: "You need to move on!" Sgt. 1st Class Maria Guerra recalled those moments while testifying Thursday during the trial of Maj. Nidal Hasan. The Army psychiatrist is charged with killing 13 people and wounding more than 30 others during a rampage at the sprawling Texas military base. When prosecutors asked Guerra to describe the scene, her voice began breaking. I see bodies. I see bodies everywhere. And I see blood," she said. No one is moving. There was no movement. There was no sound. So I yelled out, 'Is everybody OK? ... I started hearing, 'Help me. I'm bleeding. I've been shot. Help me.' Hasan - who is acting as his own attorney but has said little during the trial - raised a rare objection when Guerra said she heard the gunman silence a woman who was crying out, "My baby! My baby! Hasan interrupted to ask the judge, "Would you remind Sgt. 1st Class Guerra that she's under oath?" The judge, Col. Tara Osborn, did so. But Guerra responded by saying she didn't want to change her testimony. It was the only time Hasan objected as more than a dozen witnesses testified Thursday, continuing a mostly silent defense strategy that has caused tension with his standby attorneys. Hasan took responsibility for the attack during his opening statement, and the lawyers - who have been ordered to help Hasan during the trial - believe he is trying to secure himself a death sentence. The military lawyers had asked the judge to either allow them to take over Hasan's defense or bar him from asking for their help with a strategy they oppose, saying his strategy was "repugnant to defense counsel and contrary to our professional obligations." "We believe your order is causing us to violate our rules of professional conduct," Lt. Col. Kris Poppe, Hasan's lead standby attorney, told the judge earlier Thursday before witnesses testified. Osborn refused and ordered the attorneys to resume their advisory role. The attorneys said they would appeal, though no appeal had been filed by the standby attorneys as of Thursday evening at the Court of Appeals for the Armed Forces, according to the court's clerk. A message left with the Army Court of Criminal Appeals wasn't immediately returned. Jeff Corn, a law professor at South Texas College of Law, predicted that such an appeal wouldn't delay the trial and would likely be dismissed. As sympathetic as I am to him (Poppe) and the miserable position he's in, I think he's stuck. The law is clear: If you are a standby attorney for a pro-se defendant and the defendant wants to make decisions tactically disastrous, that's his prerogative," Corn said. But it could also be an intended strategy to spare Hasan the death penalty, said Joe Gutheinz, a Houston-area attorney and former Army intelligence officer. The judge allowed him to defend himself, you raised a timely objection. That is the basis for the appeal. And it was brilliant on the part of all the parties involved. If somebody thought up this idea, it was great," Gutheinz said. I really believe this is the only way, at end of the day, he will not be executed. As during previous days during the trial, Hasan rarely spoke Thursday as witness after witness described a chaotic, bloody scene inside the Army post's Soldier Readiness Processing Center, where soldiers had been preparing to deploy. Asked to describe the rate of gunfire, Staff Sgt. Michael Davis quickly hit his hand on the ledge of the witness stand. "I still thought it was a drill, but I heard some screaming that didn't sound like it was fake," Davis said. Davis testified that he saw blood spray when someone was shot and quickly took cover under a desk. When he thought it safe to flee, he stood up but was quickly shot in the back. "It was just a cold, calculated, hard stare as he shot everything that moved," Spc. Megan Martinez testified. She recalled watching Hasan reload his pistol and the weapon's green and red laser sights sweeping through the thick, hazy smoke produced by the gunfire. "He was walking back and forth, shooting for what felt like an eternity," she told jurors.