Prakash Desai, Nathan DeSai's father, said his son was depressed because his law practice was not going well.
George Joseph reports from New York.
Nazi materials were found inside the car of attorney Nathan DeSai who shot six people and wounded another three in Houston September 26, 2015, according to media reports.
DeSai was dressed in a Nazi uniform and Nazi paraphernalia were found inside his car and apartment, according to these reports.
Captain D W Ready, head of the Houston police department's homicide division, did not confirm this. DeSai, Ready said, was dressed in some kind of military uniform and had Nazi emblems with him and at his house. The emblems, he added, may have been collector's items.
At DeSai's home, the police found vintage military equipment and paraphernalia dating back to the Civil War. 'He was wearing military-style apparel, I don't know exactly what nationality or exactly what army or anything like that,' Ready said.
'At this point we are very open minded as to the motive,' Houston's acting police chief Martha Montalvo said.
DeSai was 46 and was unmarried. He served as a former prosecutor in Dallas county and also played in a band.
According to DeSai's family, he had dinner with his parents on Sunday night and that was the last time they spoke with him. On Monday morning, they saw his car on television and called him without getting a response.
After the law firm, where he was a partner was dissolved in February, he was working from his condo, which was located near the scene of the shooting.
Kenneth McDaniel, DeSai's former law partner, said they dissolved their partnership becaue of economic reasons. McDaniel said he had not spoken to DeSai since February.
'It's a horrible situation, I don't like hearing anything that's happened... Not only to Nathan, to everybody that is involved and I don't know what to say,' McDaniel told the media.
Nine police officers were involved in the gunfight while assisting wounded citizens, Ready said. The gunman took cover behind a tree, he said.
Desai was shooting randomly at passersby as well as anybody he could place his sights on, Ready said. More than 75 expended shell casings were found at the scene, he said.
The gunman had 2,600 rounds of ammunition for his .45-caliber pistol and .45-caliber Thompson carbine rifle, which carried a 40-round clip, Ready said.
The rifle was purchased legally in 2009, and the handgun was purchased legally in 2011.
Prakash Desai, DeSai's father, told ABC News that his son was depressed because his law practice was not going well. He said Nathan was not getting any business and he had been upset for a long time.
Prakash Desai said his son lived near Weslayan and Bissonnet, the site of Monday's shooting.
The police said one victim was critically wounded and another was seriously wounded. Most of the other victims were discharged from hospitals.
DeSai earned his bachelor's degree in psychology from the University of Houston in 1993 and his law degree from the University of Tulsa in 1998. He practiced business, family and criminal law.
Jennifer Moredo, the wife of one victim, told KHOU 11 News, 'What personal problems he has going on in his life, who knows. I do know there was a confrontation with a roofing company a few weeks ago that he had a problem with and I believe he was waving around his AR, but what set him off at 6:12 this morning, I don't know.'