A gunman shot dead by police after he shot at people outside a shopping centre in Houston, Texas, was a "disgruntled lawyer", authorities said.
Nine people were injured, one of them critically, in the attack.
The suspect has not been identified. Police said he was wearing historic military attire with Nazi emblems.
Officials said he used a semi-automatic handgun, and also had a semi-automatic rifle, a knife and 2,600 rounds of live ammunition.
The guns were purchased legally and the man had a licence to carry concealed weapons, police said.
There is no indication that anyone else was involved in planning or carrying out the attack.
Six victims were taken to hospital, and three were treated at the scene after being shot at while inside their cars, the city's acting Police Chief Martha Montalvo said.
The Associated Press reported that three of the people suffered eye injuries from flying glass.
Police say they are investigating the gunman's apartment and his social media accounts to try and establish a motive.
They found other historic military paraphernalia in his apartment, dating back to the US Civil War.
The city's mayor, Sylvester Turner, told reporters: "The motivation appears to be a lawyer whose relationship with his law firm went bad."
But police said they were "not closing the door on anything".
The attack comes three days after a shooting at a shopping centre in Washington state, in which five people were killed.
The suspected gunman in that attack, Arcan Cetin, 20, was arrested after a large manhunt which lasted nearly 24 hours.
He appeared in court on Monday, charged with five counts of murder.
Court documents say he confessed to shooting all five victims with a rifle.
Mr Cetin was born in Turkey and is a legal US resident, officials say.
The motive for the shooting is not known but the suspect's family says he has a history of mental problems.