Two black men were arrested at the store on Thursday, after police said the Starbucks manager asked them to leave the store because they hadn't bought anything and asked to use the restroom, which is against company policy.
An attorney for the two men said they were waiting for a third person to arrive for a business meeting at the cafe.
Video of the arrest quickly went viral.
Among the demonstrators was Melissa DePino who captured the video of the arrest being passed around on social media.
"There's nothing more to the story than what you see in the video," said DePino. "And when people say 'there must be more to the story' that's part of the problem in my view."
Leaders from several organizations attended Sunday's protest at the store, demanding that the manager be fired and thanking the customers in the store who interjected during the arrests.
"They spoke up for those two black men. They put their bodies on the line," said Asa Khalif. "They spoke up and they challenged the police and they filmed. This is what allies do."
The protest spilled into the store where Starbucks Regional Vice President Camille Hymes spoke to the crowd, addressing calls for the manager's firing.
"We take full responsibility and put her in a position that did not set her up for success or for those two men," said Hymes.
The incident sparked an internal investigation within the Philadelphia police department, leading the commissioner to release a statement last week:
"These officers did absolutely nothing wrong," said Philadelphia Police Commissioner Richard Ross. "They followed policy. They did what they were supposed to do."
It also led Starbucks CEO Kevin Johnson to release an apology, calling the arrest a "disheartening situation" that led to a "reprehensible outcome."
He also offered to apologize face-to-face to the two men and said a company-wide meeting will be held this week to address the incident.
After their arrest, the two men were released early Friday morning.
The Philadelphia District Attorney declined to press charges because of a lack of evidence.
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