The deadly attack at a 101st Airborne Division brigade command center in Kuwait also wounded 15 other soldiers Sunday, three seriously.
Akbar had reportedly told his mother he feared persecution because he is a Muslim and had been reprimanded recently for insubordination.
The woman who said she is Akbar's mother, Quran Bilal, told The Tennessean of Nashville that she was concerned her son might have been accused because he is a Muslim. She said he was not allowed to participate in the first Gulf War because of his religion.
"He said, `Mama, when I get over there I have the feeling they are going to arrest me just because of the name that I have carried,'" Bilal, of Baton Rouge, La., told the newspaper for a story published in Monday's editions.
Akbar, of the 101st's 326th Engineer Battalion, was in custody, said George Heath, a civilian spokesman at Fort Campbell. Heath said Akbar had not yet been charged with a crime Monday but was the only person being questioned in the attack.
Heath said Akbar should eventually come back to Fort Campbell, though military officials could convene a court-martial in Kuwait. He said he was not sure what kind of penalty Akbar could face.
Jim Lacey, a correspondent for Time magazine, told CNN that military criminal investigators said Akbar was recently reprimanded for insubordination and was told he would not join his unit's push into Iraq. Heath also said Akbar had been having "an attitude problem."
The motive of the attack "most likely was resentment," said Max Blumenfeld, another Army spokesman.
The Los Angeles Times reported in Monday's editions that soldiers said they overheard Akbar declare: "You guys are coming into our countries and you're going to rape our women and kill our children."
A neighbor in Akbar's apartment complex outside Fort Campbell in Clarksville, Tenn., said Akbar was a devout Muslim. Willie Shamell Jr. said he thought racial discrimination had affected Akbar's military career. Akbar is black.
"I know he didn't like his unit that much," Shamell told The Tennessean. "He didn't get promoted. I had asked him how that had worked. A lot of people feel that (discrimination) is there at Fort Campbell."
Akbar's family moved to Louisiana last summer from Moreno Valley, 60 miles east of Los Angeles, neighbors said. Jim Gordon, who lived across the street in Moreno Valley for five years, said he didn't know the family well but that police often went to the house. He said the residents played loud music and had occasional domestic disputes.
Akbar was born Mark Fidel Kools. His mother said she changed his name to Hasan Akbar after she remarried when he was a young boy. Public records found by The Associated Press showed listings for Hasan Akbar under the name Kools as well.
One address for Mark Fidel Kools in Los Angeles is the Bilal Islamic Center, a collection of small buildings and mobile homes around a mosque that's under construction.
"He was never in trouble," Abdul Karim Hasan, the center's imam, or religious leader, told The Tennessean. "He was always standing on the outside of any kind of tussles between kids."
Bilal said the military had not contacted her and expressed disbelief in the accusations against her son.
"He wouldn't try to take nobody's life," she said. "He's not like that. He said the only thing he was going out there to do was blow up the bridges."
A message left by The Associated Press at a listing for Bilal was not immediately returned Sunday.
The Army identified the dead soldier as Capt. Christopher Scott Seifert, 27, of Easton, Pa. Heath said Seifert was married. A spokesman for Seifert's mother and father - Thomas and Helen Seifert, also of Easton - said the family would not immediately speak with reporters.