"A this point, we're very open-minded in terms of the motive," acting Houston police chief Martha Montalvo said. Police added that the shooting did not appear to be terrorism.
Houston Mayor Sylvester Turner, who was on a trade mission to Cuba when the shooting occurred, said DeSai may have carried out the attack because he was upset about troubles at his law practice.
"The motivation appears to be a lawyer whose relationship with his law firm just went bad," Turner told reporters. In a separate interview with KTRK, he said DeSai was "either fired or had a bad relationship with this law firm".
DeSai graduated from the University of Tulsa law school in 1998 and ran a small firm where he practiced business, criminal and family law, according to his state bar association page.
His law partner, Kenneth McDaniel, said the two of them worked together for 12 years before parting ways in February. He disputed claims that DeSai was "disgruntled" with the firm or that he was fired from his job.
"That's the farthest thing from the truth," McDaniel told the Chronicle. "It was simply a matter of economics. We couldn't afford to operate as a partnership anymore."
DeSai's father, Prakash DeSai, told KTRK that the disbanding of the law firm weighed heavily on his son, whom he last saw the night before the shooting.
"He's upset about the law practice not going well - financial reasons," Prakash DeSai told the station.
John Elmore, the property manager for The Oaks at West University, where DeSai lived, told KTRK that he had been behaving erratically in the months leading up to the shooting. He said he believed DeSai was doing law work out of his apartment and said he had been acting as if someone was "out to get him".
In August, Elmore said, DeSai pulled a gun on a construction crew working on the complex's roof, apparently mistaking them for burglars.
"They were scared for their life," Elmore said. "They felt like they were going to get shot."
DeSai began his rampage around 6:30am on Monday (local time), unloading his semiautomatic handgun at morning commuters on the four-lane road outside the strip mall.
More than a dozen officers from three agencies responded to calls for an active shooter and found the man "shooting randomly at passers-by, as well as anybody he could put his sights on," Houston police Captain Dwayne Ready said. Officers engaged in a standoff, as the shooter took cover behind his car and a tree while he exchanged fire with police. After about 20 minutes, officers shot and killed him. Police did not say how many times he was struck.
Nine people were injured during the shooting, some by shattered glass, and the gunman's bullets hit numerous vehicles, according to police. Six people were taken to hospital, police said, one in critical, one in serious and one in good condition as of Monday afternoon. Three others were discharged the same day and another three were treated at the scene.
Eduardo Andrade said he was on his way to the gym Monday morning when two of the shooter's bullets struck his Audi A3, one lodging between his dashboard and windshield.
"It is so random," he told the Chronicle. "If I were going a little faster or a little slower, the bullet would have had a different trajectory."
