ST. LOUIS — Ferguson police are investigating a fight between members of Michael Brown Jr.’s family on Oct. 18, stemming from a disagreement over who has the right to sell commemorative shirts.

Pearlie Gordon, 54, the mother of Michael Brown Sr.’s wife, Calvina, said she was one of three people selling “Justice for Mike Brown” T-shirts from a tent outside Red’s BBQ when a group of 20 to 30 people rushed them.

Gordon said Lesley McSpadden, Michael Brown Jr.’s mother, told her she couldn’t sell the shirts. Gordon said she told her she was Michael Brown Sr.’s mother-in-law, and unless McSpadden had a patent on her son’s name, she was going to continue. Gordon said in an interview that she and her son-in-law sell shirts, bandannas and other Brown memorabilia at the tent and over the Internet.

Gordon was “repeatedly struck in the back and left side of the head by an unknown subject,” according to the report.

She said McSpadden ran up and punched her. Gordon told police that her friend, Tony Petty, was also attacked and taken by ambulance to a hospital. Gordon said $1,500 in merchandise and $400 were stolen in the incident.

Lynne Perkins, a lawyer for McSpadden, said, “My client denies that she assaulted anyone.”

The report says a witness took video of the fight, but the police haven’t convinced her to turn it over.

At McSpadden’s request, Ferguson did not initially release the incident report to media.

Ferguson city clerk Megan Asikainen filed suit in St. Louis County to get a court ruling on a request from KTVI reporter Chris Hayes on whether it was an open record; St. Louis County Presiding Judge Maura McShane on Wednesday told the Ferguson city attorney the report was an open public record.