The June incident started inside a Starbucks in downtown Chicago, and was recorded on a cellphone camera by a local television photographer who was there at the time. In the video, a man later identified as Boucher can be heard shouting, "You're disgusting!" and other insults in the presence of other customers and employees.
The video starts after Boucher has already begun shouting; he reportedly was enraged because someone accidentally spilled coffee on him.
The incident escalated after Boucher left the Starbucks and spat on a 30-year-old man and a 34-year-old woman outside, police said.
In additional video footage, Boucher, who is white, can be seen hurling racist insults at two black bystanders in broad daylight. He appears to be wearing a cream-coloured suit that has visible drink stains.
"Shut up, slave! Do not talk to me!" Boucher yells at the two black men. "Your children are disposable vermin!"
Someone who appears to be a Starbucks employee tries to intervene in the video, but Boucher continues yelling toward one of the men, who is walking away: "Get on all fours! Do not walk off on two legs!"
Shortly after that, police said, Boucher punched a 59-year-old man without provocation. The man, who was reportedly homeless, was taken to a hospital with an eye injury, according to ABC7 News.
Bystanders detained Boucher near the Starbucks until officers arrived and arrested him, police said.
Gerald Mitchell, the 30-year-old man who was spat on and who helped detain Boucher, told the Chicago Sun-Times in July that he hoped the belligerent man learned something from the experience.
"I try to see the good in people," Mitchell told the newspaper. "I don't know his background. I would try to give him the benefit of the doubt. I just know it was downright wrong. Disgusting."
A Starbucks spokeswoman told the Washington Post in June that there was "absolutely no tolerance for this type of behaviour in our stores" and that they were grateful to the employee who stepped in until police arrived.
Starbucks spokesman Reggie Borges said today that the company did not have further details about Boucher's case or whether he had a history as a "problem customer" at the downtown Chicago location, as some employees had suggested to local media.
"It goes without saying we expect a civil engagement and peaceful discourse in all of our stores, and we want to make sure all of our customers feel welcome and have a positive experience in our stores," Borges said.
Boucher's next court appearance is scheduled for October 10.