The victim, identified as Patrick Wright, was shot twice in the chest on Avenue R at the corner of 36th Street.
According to a probable cause affidavit, an Uber customer staying at a nearby Airbnb told police Wright had been harassing his driver.
He said he saw Wright reading out the Uber driver's license plate, proclaiming, "This is G-town," and then lunging at the Uber driver through an open window.
The witness told investigators that he heard the gunshots after Wright lunged.
Police say they located the Uber driver a few blocks away, but that he denied being involved in a shooting and claimed he was on his way to the Airbnb when officers pulled him over.
Investigators say a gunshot residue test implicated the driver in the crime, and he was charged with murder.
But Tuesday, police said they discovered a flaw with their gunshot residue tests. They also say that video evidence they obtained casts doubt on the driver's involvement.
Asked if the discovery about faulty gunshot residue tests would impact any other cases, the district attorney's office would only say that it's reviewing the matter with the Galveston Police Department.
Galveston police didn't respond to requests for specifics about the tests.
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