Navy Cmdr. Charles Springle, 52, of Wilmington, N.C., Pfc. Michael Edward Yates Jr., 19, of Federalsburg, Md., and Dr. Matthew Houseal, of Amarillo, Texas, have been identified as three of the victims in Monday's shooting. The names of the two others have not been released.
Yates' mother, Shawna Machlinski, said two Army representatives came to her home on the Eastern Shore and said her son was killed by what they called "friendly fire." Machlinski, who last spoke to her son on Mother's Day, said he had talked about the alleged shooter, 44-year-old Sgt. John M. Russell.
She said he told her Russell was deeply angry at the military after three tours of duty in Iraq.
"He said, 'Man, this guy's got issues,'" said Machlinski. She said her son wasn't more specific about Russell's problems and that he told her he got along with him.
The case, the deadliest of the war involving soldier-on-soldier violence, has cast a spotlight on combat stress and emotional problems resulting from frequent deployments to battle zones in Iraq and Afghanistan.
Iraq war veteran Paul Rieckhoff says while incidents like the clinic shooting are extremely rare, the rampage highlighted the need for better mental health care on military bases in Iraq.
"This is a wakeup call," Rieckhoff, who founded the organization Iraq And Afghanistan Veterans Of America after returning home in 2004, told CBS' The Early Show.
"We need qualified mental health professionals," Rieckhoff, said, adding that there is a "huge stigma" attached to soldiers seeking and receiving treatment.
Helping soldiers deal with those problems was Springle's life's work, said Bob Goodale, a friend and colleague, and director of behavioral mental health for the Chapel Hill, N.C.-based Citizen-Soldier Support Program. The Pentagon also confirmed Springle had been killed.
"He regarded it as very important work," Goodale said. "We all who work in this know that it is difficult. This is an example of how difficult."
Bud Schertler, executive director of the Texas Panhandle Mental Health and Mental Retardation, said Houseal's wife confirmed the doctor who had worked at the center for 12 years had been killed.
"He was dedicated to his patients. He was a family man, very thorough diagnostician. We couldn't ask for a better psychiatrist," Schertler said.
He said Houseal had volunteered to go back to assist in Iraq and was called up for duty. He did not know Houseal's rank or what branch of the service he was in. He said Houseal had six children.
A clinic spokesman called Houseal "a brilliant man and he helped a lot of people."
"You always hear stories about doctors not taking time with patients - that was his life, helping people," Jim Womack said.
The clinic in Baghdad was operated by the 55th Medical Company, a Reserve unit headquartered in Indianapolis. Capt. Adam Jackson, a spokesman for the unit, said he could release no information on the clinic shooting or the people involved. Two of the victims were officers assigned to the Iraq clinic and the three others were enlisted soldiers, said Maj. Gen. David Perkins.
Machlinski said her son was being treated at the clinic because he was having difficulty readjusting to life in Iraq after visiting Maryland for most of April, when he seemed angry and distant.
"I think he just had a lot on his mind and had a hard time adjusting to civilian life," she said.
Machlinski said that while she was angry at Russell, she is angrier at the military for not doing more to intervene and that she could understand the stress Russell must have been under.
"I do have some sympathy and I do know that I can forgive him," Machlinski said. "I kind of blame the Army for not protecting my son. Someone should have helped this sergeant way before he got this bad."
Yates had a 1-year-old son, who lives with his mother in Seaford, Del., about 10 miles from Federalsburg, Machlinski said.
A commander since 2002, Springle went by his middle name of "Keith" and had been in the Navy for 21 years. A Navy spokesman said Springle left behind a wife and two children.
Springle, who was a clinical social worker, also was director of the Camp Lejeune Community Counseling Center and worked closely with Goodale's program. The two helped present training called, "Painting a Moving Train: Preparing Community Providers to Serve Returning Warriors."
Goodale said Springle understood deploying to Iraq was part of his job and planned to keep helping service members with mental problems when he returned. Their presentation outlines potential traumas experienced by service members and the barriers that keep them from being treated.
"He wasn't talking about getting out," Goodale said. "This epitomizes how important the work is. We have to find better ways to reduce the stigma. To work on the acceptance of combat stress as a real thing. It has been for centuries, and we must persevere."