A Cubs fan who flashed a hand gesture associated with white supremacists has been banned for life by the Cubs in the latest incident that shines a light on Wrigley Field’s longstanding reputation for racist behavior.

After a daylong investigation Wednesday, the Cubs found the fan who used the gesture behind NBC Sports Chicago reporter Doug Glanville during Tuesday’s broadcast. Team president of business operations Crane Kenney says the fan, who was not publicly identified by the Cubs, will be banned from Wrigley Field.

During the game Tuesday, Glanville, who is black, stood beside the Cubs’ dugout, talking on-air to announcer Len Kasper about the Cubs’ offense when a fan in the background started making several gestures.

The bearded fan, who was wearing a grey Cubs sweatshirt and blue bottoms, held an upside-down “OK” sign — which has been associated with white nationalists — behind Glanville’s head before the broadcast cut to a graphic.

While the gesture has also been used as part of the “circle game,” in which someone tries to trick a friend into looking at them making a similar hand gesture, Kenney said on 670 The Score that team officials met and decided it was more likely the gesture was used in a “racist way.”

By Wednesday evening, the Cubs knew the fan had purchased the ticket through StubHub, but failed reach the fan by phone after multiple attempts, so they sent a letter notifying him of the team’s decision to indefinitely bar him from Wrigley Field and other ticketed areas. The ban is effective immediately.

Kenney said if the fan attempts to enter Wrigley Field, he may be subject to prosecution for criminal trespass.

Glanville, who said he became aware of what happened after the segment aired, offered his appreciation for the Cubs’ and NBC Sports Chicago’s handling of the incident.

Team president Theo Epstein called the incident “truly disgusting.”

“It gave me shivers to watch that, that that would take place at Wrigley Field,” Epstein said.

But this isn’t an isolated event on the North Side.

For years, Wrigley Field has had a reputation among the league for being racist. Former Cubs outfielder Jacque Jones and former manager Dusty Baker said they received racist hate mail from fans during their time in Chicago. Former Cubs pitcher LaTroy Hawkins was harassed when he would walk to his car and also received hate mail containing the N-word.

It’s such a notable problem that Twins outfielder Torii Hunter had a partial no-trade clause that included the Cubs among teams that were off limits.

And it’s still a problem.

Last September, a fight broke out in the Wrigley bleachers and a fan hurled racial slurs during Hispanic Heritage Night. And most recently, Major League Baseball launched an investigation into racist messages sent to Cubs relief pitcher Carl Edwards Jr. on social media.

Jill Anderson, a Cubs fan from the northwest suburbs, witnessed last season’s brawl in the bleachers. In her experience, the Cubs have taken the right steps to address problem fans.

“You have to be proactive and say something and not tolerate it,” said Anderson, who has been harassed in the bleachers. “I think it’s everybody’s job not to tolerate it, and not just the people who work here but you can’t just be like, ‘Oh, they’re at the ballpark drinking.’ No. If it’s bad, it’s bad. There’s no excuse, there’s no tolerance for it.”

Anderson also believes alcohol plays a factor in these incidents.

“When people are drinking,” she said, “they say things without thinking.”

Fan Schuyler Woods believes these are isolated events.

“I’ve been coming here since I was 8,” said Woods, who is black, “and I have never had a bad experience.”

Outfielder Jason Heyward said he heard about the most recent incident Wednesday before he got to ballpark.

His reaction?

“Nothing,” he said. “I’ve been black my whole life.”

Outfielder Kyle Schwarber condemned such behavior.

“There’s no place for it here,” Schwarber said. “”You don’t want to see it around any ballpark. This is the Friendly Confines.”

Epstein said the fan’s actions don’t represent the Cubs’ values.

“It’s important to have a strong response and send a message that this is a place of inclusion,” Epstein said. “We are a welcoming organization … We value diversity; we value inclusion.”