U.S. Navy Adm. Mike Mullen, Joint Chiefs of Staff chairman, greeted the bodies in flag-draped boxes Wednesday when they arrived at Dover Air Force Base in Delaware, CNN reported Thursday.
Army Sgt. John M. Russell of Sherman, Texas, was charged in the five deaths Monday at Camp Liberty near the Baghdad international airport.
Military officials said Russell was escorted back to his quarters from the clinic after he "became hostile and an altercation broke out." Russell later seized another soldier's weapon and commandeered a vehicle to return to the clinic where he opened fire, officials said.
"I feel for him, but at the same time I am very angry at him," Shawna Machlinski, mother of victim Army Pfc Michael Yates, 19, of Federalsburg, Md., told CNN.
The military has begun two investigations into the incident -- one criminal and the other an examination of the military's mental health services and ways to prevent similar incidents in the future.
Celebrity Families of 2014 [PHOTOS]