MIAMI — For anyone familiar with driving in Miami, gridlock on the Brickell Avenue Bridge is not unusual. Stretching across the Miami River, the drawbridge is a primary roadway connecting the city's congested downtown and its bustling financial center. But on Monday, traffic on the bridge and nearby roadways came to a standstill rather unexpectedly.

A large group of young black activists on bicycles, many carrying colorful homemade signs, swarmed the street, blocking cars as they protested for fair housing. Frustrated motorists could be seen on video honking loudly as they tried, unsuccessfully, to inch past the strong-willed protesters and their bikes.

It didn't take long for the peaceful demonstration to turn into an ugly confrontation involving a gun and repeated use of the n-word that has since sparked widespread backlash and resulted in the arrest of a man who could now face hate-crime charges, Miami officials announced Tuesday.

Mark Allen Bartlett, 51, was arrested Monday and charged with carrying a concealed firearm, a felony, according to court records. But in a statement Tuesday, Miami-Dade State Attorney Katherine Fernandez Rundle said she was "outraged at the reported acts depicted in the videos taken during this incident," adding that she had assigned the hate crimes unit chief to "immediately investigate and handle this case."

"I am committed to filing the appropriate charges and to vigorously prosecute this case to the fullest extent of the law," Rundle said.

Bartlett could not be reached for comment early Wednesday morning and court records did not list an attorney.

In an interview with WPLG, Bartlett said he had been trying to protect his girlfriend, Dana Scalione, and defended his use of the n-word.

"The reason why we use that word, the reason why Chinese people use the word, why Japanese people, European people, the reason why everybody uses that word is because black people use that word," he said.

He went on to describe racial slurs for Puerto Ricans, Jews and Asians before saying: "Nobody uses those words anymore. Why? Because Puerto Ricans don't say that to each other. Because Asian people don't say that to each other. Because the Jewish people don't say that to each other. The only ones that continue to say it are black people. So what's the first thing in my head or most people's heads? Unfortunately, it's the n-word."

Now-viral footage of the heated exchanges shared online Monday by Dream Defenders, a Florida civil rights group that organized the protest, showed a white man identified as Bartlett, allegedly hurling obscenities at several black teens and calling them the n-word as he approached them brandishing a black handgun.

"These kids were protesting and a gun was pulled out on a kid," Dwight Wells, a member of Dream Defenders, said during a news conference Tuesday afternoon.

The intense clash appeared to begin when an irate Scalione engaged the protesters, many of whom were young black men, and started yelling at them. The demonstration in Miami's Brickell neighborhood coincided with a larger annual movement that has occurred across South Florida over the past several years. The "Wheels Up, Guns Down" events, which take place on Martin Luther King Jr. Day, are meant to promote peace, but have generated controversy and usually ended in a number of arrests over illegal ATV and dirt bike riding.

"Who do you think you are, blocking the streets?" Scalione asked in the video, as car horns blared in the background. The teens could be seen circling Scalione on their bikes and arguing with her.

"You'll end up in jail," she said, sarcastically clapping her hands. "Good job."

After one protester asked Scalione to leave them alone, she began pleading with them to move their bikes.

"I have kids I need to pick up, please sir," she said to a protester who had parked himself in front of a line of cars. "I have kids I need to pick up and we need to get them."

She added: "This isn't funny."

The situation escalated when Scalione got out of her car for a second time, according to Dream Defenders.

In a video shared Monday on Twitter, Scalione is surrounded by at least four teens and is visibly enraged.

"I said don't touch me," she yelled. A person can be heard responding, "I didn't touch you."

Pushing one of the young men away from her, she screamed, "You just ran over me. You just ran over my foot with your tire."

More cyclists joined the melee as Scalione engaged in a shouting match with a protester in a red tank top, their faces just inches apart.

"You just touched me, you bunch of thugs," she said, turning to walk away from the group, who shouted expletives at her, calling her an offensive word for females and a "white a--."

In the background of the video, a man, identified by police as Bartlett, wearing blue jeans and a pink T-shirt could be seen jogging toward Scalione.

"Woah," one of the teens yelled. Others hurriedly jumped on their bikes and began pedaling away.

Gripped in the Bartlett's right hand was what appeared to be a black handgun.

"Who did it?" he asked.

Scalione pointed at the teen in the red tank top.

Marching up to him, Bartlett unleashed a load of expletives in the video, telling the teen to "Get ... out of here," before directing more curse words and a racial epithet at the group.

"Y'all going to make the news," the person recording the video taunted. "That's fine," Scalione shot back.

Bartlett told WPLG that all he saw was "15 people running across the street toward my girlfriend," later adding that his only regret was not having a concealed carry permit.

"My first reaction is I have a gun on me," he said. "Whether I have a gun on me or not, I'm running to see and to protect my family. I had a gun though. It wasn't loaded. I ran out there. You can see I never pointed it. I never threatened anybody. I just needed it in case something were to happen."

According to an arrest affidavit, when police stopped Bartlett after the confrontation and conducted a search of his Range Rover, they found a loaded black Springfield Armory pistol without a holster in the rear back pouch of the front passenger seat.

Bartlett told police that he did not have a concealed carry permit, but once in custody seemed shocked by the arrest, the affidavit said.

"Why am I being arrested, when those kids are free to ride around?" he said. "I did pull out my gun but I never pointed it at them."

Monday's incident has since been widely rebuked, with many slamming Bartlett and Scalione as "racists." People also reported seeing several different trucks driving around Miami on Tuesday with LED screens bearing Bartlett's photo and the words, "Mark Allen Bartlett points guns at kids" and referencing his use of the slur.

Others, however, argued that that the young protesters were also at fault. Beyond slinging insults at Scalione, video published by CBS Miami showed the teens blocking major intersections and captured one young man appearing to urinate off the side of the bridge.