Fort Hood, Texas (CNN) -- Army investigators on Sunday asked troops and civilians for help in the probe of a deadly mass shooting at Fort Hood last week, saying some who fled the gunfire might have evidence.



"The Fort Hood office of the U.S. Army Criminal Investigation Command is seeking any military or civilian personnel who may have left the scene ... with gunshot damage such as damaged privately owned vehicles, personnel clothing, etc.," investigators said in a written statement. "CID is also seeking any military or civilian personnel who may have inadvertently left the scene of this incident with material that could be used as firearms residue related evidence such as shell casings inside the boot, etc."



The statement said such objects would help Army investigators and the FBI "in their bullet trajectory analysis of the scene, to insure the comprehensiveness of the ongoing investigation."



Thirteen people -- a dozen soldiers and a civilian -- died Thursday in the shooting at the Fort Hood Army Post. Some 42 people were wounded, according to the post's public information office. It was unclear how many of those suffered gunshot wounds.



Among the wounded was Pvt. Joseph Foster, 21, who was preparing for his January deployment to Afghanistan when he was hit in the hip during the attack. With his wife and 6-week-old daughter beside him, he told reporters gathered outside his home Sunday that it was difficult to accept such an attack on his own post.



"Not here at home -- but as we've seen, anything is possible," Foster said. "We are at war."



As of Sunday, 16 gunshot victims remained hospitalized plus the suspect, Maj. Nidal Malik Hasan, spokesman Col. John Rossi told reporters. He did not say where all those hospitalized were being treated. Of the 16, seven were in intensive care, he said.



When Staff Sgt. Alvin Howard's wife heard he was hurt at the post, her feelings were "indescribable," she said Sunday.



Kaneesha Howard told reporters her husband was set to deploy to Afghanistan in January. In 2003, he was deployed to Iraq, she said.



Daughters, Alanna, 9, and Kristen, 7, were shaken by the event.



Alanna said of her younger sister: "She started crying when we went to the hospital because she [had] never seen her dad bandaged up like that."



Howard was shot in the shoulder and was recovering in the hospital, his family said. They were unsure when he would be released.



Rossi said Hasan, a 39-year-old licensed Army psychiatrist who worked at a hospital on the post, is no longer on a ventilator, but remained in critical but stable condition and in intensive care at Brooke Army Medical Center.



Authorities have not identified a motive in the attack at Fort Hood's military processing center, where soldiers report before they head to war.



Efforts to assist those affected by the incident, including family members of soldiers at the post, were ongoing, Rossi said. Fort Hood was awaiting the arrival of two specialists in child psychology and disaster management, he said. "This is not just for those directly affected by this tragedy," Rossi said, noting that effects from trauma sometimes are not immediately apparent.



However, he said, soldiers are trained to respond to violence by controlling and securing the scene.



"Their training kicks in, and that's what we saw," Rossi said. "The troubling part of it is it happened here in our own house."



Army Criminal Investigation Command spokesman Chris Grey said Saturday that all evidence indicates that the suspect acted alone and there was no indication of "friendly fire."



The processing center has been moved to another location so its work can continue while investigators work at the crime scene, Rossi said Sunday.



He told reporters he did not know Hasan's schedule on the day of the shooting, but "my understanding is that there was no purpose for him" to be in the processing center.



The remains of those killed are currently at Dover
Where is the suspect now? Who is still hospitalized How many peopel died? The soldier was wounded where? How many died in the attack? How many were killed?
hospitalized 16 gunshot victims Thirteen people Fort Hood a dozen soldiers and a civilian Thirteen people -- a dozen soldiers and a civilian -- died
question: Where is the suspect now?, answer: hospitalized | question: Who is still hospitalized, answer: 16 gunshot victims | question: How many peopel died?, answer: Thirteen people | question: The soldier was wounded where?, answer: Fort Hood | question: How many died in the attack?, answer: a dozen soldiers and a civilian | question: How many were killed?, answer: Thirteen people -- a dozen soldiers and a civilian -- died