First an argument, then gunfire, and two young women lay wounded Sunday evening inside a downtown Atlanta sub shop.

One of those women, identified as 26-year-old Brittany Macon, was later pronounced dead. They were coworkers at a Subway connected to a Circle K on Northside Drive, two blocks south of Mercedes-Benz Stadium. A customer became enraged over the amount of mayonnaise on a sandwich and pulled out a gun shortly after 6:30 p.m., according to Atlanta police.

The other woman, a 24-year-old, was shot in front of her 5-year-old child and is in critical condition at a hospital. The shooting brought a host of Atlanta police officials to the scene Sunday night, including interim police Chief Darin Schierbaum.

“What you are seeing behind me is the result of a tragedy,” Schierbaum told reporters from outside the Subway. “A senseless tragedy that we’ve seen numerous times throughout the year where an argument leads to gunfire, and now we have someone dead.”

Within a few hours, a crucial tip helped investigators identify a 36-year-old Atlanta man as a suspect, and he was arrested late Sunday not far from the restaurant, according to police. Deputy police Chief Charles Hampton declined to release his name Monday, citing the ongoing investigation.

The name of the injured victim was also being withheld. Willie Glenn, who co-owns the Subway location, told Channel 2 Action News both women started working there earlier this month and were considered “model employees.”

“It breaks my heart to know that someone has the audacity to point a weapon and shoot someone for as little as too much mayonnaise on a sandwich,” Glenn said.

A frustrated Schierbaum said Sunday that arguments are the leading cause of the homicides his department has investigated in 2022. Atlanta has seen 82 homicides in 2022; the number at this time last year was 70. Authorities investigated 160 homicides in 2021, up from 157 in 2020. The agency previously had reported it worked 158 cases last year and updated the total after a review of department data. Last year’s homicide total was the highest since 1996.

Just this year, arguments at Atlanta restaurants and bars have led to deadly gunfire at least a half-dozen times, and most of those victims have been young adults. Those scenes have included strip clubs, sports bars, fast-food restaurants and a southwest Atlanta bowling alley, where police believe 31-year-old mother LaKevia Jackson was killed in the parking lot after arguing with a stranger in the next lane over a bowling ball.

“We need individuals to talk out their disputes, walk away and do not pick up guns,” Schierbaum said Sunday. “We can take down drug operations that breed violent crime, we can dismantle gang organizations that breed violent crime, we can stop robbery crews that breed violent crime. We cannot stop someone who is mad because there is too much mayonnaise on their sandwich.”

Despite pleas from police leaders, shootings resulting from verbal arguments have continued. Five hours after the Subway shooting and several miles north, Atlanta police responded to another deadly shooting in a Buckhead parking lot. Investigators said one man was killed and two others were injured when an argument escalated to gunfire in the 2200 block of Peachtree Road.

In that incident, Atlanta police were hoping surveillance footage would help them identify the shooter. No arrests have been announced in the Peachtree Road case.

Anyone with information on either incident is asked to come forward. Tipsters can remain anonymous, and be eligible for rewards of up to $2,000, by contacting Crime Stoppers Atlanta at 404-577-8477, texting information to 274637 or visiting the Crime Stoppers website.

— Staff writer Alexis Stevens contributed to this article.