Authorities say the Kuwait-born Abdulazeez, 24, of Hixson, Tennessee, unleashed a barrage of fire at a recruiting center in Chattanooga, then drove several miles away to a Navy and Marine reserve center where he shot and killed four Marines, and wounded a sailor who died later in a hospital. Abdulazeez was fatally shot by police.
News of Abdulazeez’s uncle came as President Barack Obama honored the victims of the attacks and those mourning their loved ones in Chattanooga.
“We draw strength from yet another American community that has come together with an unmistakable message to those who would try and do us harm: We do not give in to fear. You cannot divide us. And you will not change our way of life,” said Obama.
Obama ordered, in a proclamation sent to media outlets, that all U.S. flags at the White House, U.S. public buildings and military posts be flown at half-mast until Saturday evening.
Abdulazeez spent several months in Jordan last year under a mutual agreement with his parents to help him get away from drugs, alcohol and a group of friends his relatives considered a bad influence, according to a person close to his family. That person also spoke on condition of anonymity out of concern it would have business repercussions.
An FBI spokesman has declined to comment on that information.
Authorities are struggling to understand Abdulazeez's motive. Investigators have described their search through the remnants of his life as a domestic terrorism investigation, but nothing about his comings and goings had caught their attention before the rampage Thursday morning.
An official familiar with the investigation said investigators have found writings from Abdulazeez that reference Anwar al-Awlaki, a U.S.-born cleric who was killed in an U.S. drone strike in September 2011, and who U.S. officials believe played an important role in encouraging and inspiring attacks in the U.S. The official was not authorized to discuss by name an ongoing investigation, and spoke on condition of anonymity.
However, investigators have said they have not found evidence that anyone had specifically directed Abdulazeez to carry out the attacks.
Adding to the muddled picture, many who knew him have described a clean-cut high school wrestler who graduated from college with an engineering degree and attended a local mosque.
"Everything seemed fine. He was normal. He was telling me work was going great," said one of the friends, Ahmed Saleen Islam, 26, who knew Abdulazeez through the Islamic Society of Greater Chattanooga and saw him at the mosque two or three nights before the attacks.
But the person close to the family talked about a different side of Abdulazeez’s life. He was first treated by a child psychiatrist for depression when he was 12 or 13 years old. Several years ago, relatives tried to have him admitted to an in-patient program for drug and alcohol abuse, but a health insurer refused to approve the expense.
Court records point to a volatile family life. His mother filed for divorce in 2009 and accused her husband of sexually assaulting her and abusing their children. She later agreed to reconcile.
A year after graduating from college with an engineering degree, Abdulazeez lost a job at a nuclear power plant in Ohio in May 2013 because of what a federal official described as a failed drug test.
Recently, Abdulazeez had begun working a night shift at a manufacturing plant and was taking medication to help with problems sleeping in the daytime, the federal official said, adding that Abdulazeez had a prescription for muscle relaxants because of a back problem.
Abdulazeez was arrested on a charge of driving under the influence April 20. He reportedly told a Chattanooga police officer he had been with friends who had been smoking marijuana. He had white powder on his nose when he was stopped, and reportedly told the officer he had sniffed powdered caffeine.
The arrest was "important" because Abdulazeez was deeply embarrassed and seemed to sink further into depression following the episode, the person close to the family said. Some close relatives learned of the charge only days before the shooting.
The family believes his personal struggles could be at the heart of last week's killings, the person close to the family said.
Al Jazeera and The Associated Press