Trump Staffers Test Positive for Coronavirus Before Tulsa Rally, Protester in 'I Can't Breathe' Shirt Arrested

President Donald Trump's in-person return to the campaign trail is proving to be concerning, hours before he's set to address supporters.

On Saturday, Trump, 74, is scheduled to speak at a rally stop in Tulsa, Oklahoma, at 7 p.m. local time, for a controversial appearance that was pushed back "out of respect" for the Juneteenth holiday.

Despite the nationwide uproar over racial injustices, the campaign event is proving to be problematic given the ongoing novel coronavirus (COVID-19) pandemic.

Held at the Bank of Oklahoma Center, which seats 19,000 guests, the indoor event could potentially expose attendees to the virus — a fact the Trump campaign recognized when it forced ticket-buyers to sign a waiver preventing them from suing if they test positive for COVID-19 afterward.

Crowds flocked outside the BOK Center early in the morning, with one peaceful protester being arrested by police while wearing an "I Can't Breathe" T-shirt, referencing the killing of George Floyd by police in Minneapolis last month.

BRENDAN SMIALOWSKI/AFP via Getty Images Tulsa Police take Sheila Buck into custody near an entrance to a security checkpoint for a rally with President Donald Trump at the BOK Center on Saturday in Tulsa, Oklahoma.

MSNBC reporters captured the moment on camera, showing the woman, identified as Tulsa resident Sheila Buck, being taken into custody despite having a ticket for the event. The Tulsa Police Department later said on Facebook that they "were requested by Trump Campaign Staff to remove an individual from the secure area of the rally."

"Ms. Buck was in an area that is considered a private event area and the event organizer, in this case the Trump Campaign, can have people removed at their discretion," the department said on Facebook.

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Win McNamee/Getty Images Supporters of President Donald Trump gather to attend a campaign rally at the BOK Center on Saturday in Tulsa, Oklahoma.

When the woman appeared to refuse compliance, officers put the woman in handcuffs and escorted her away. According to police, Buck was booked for "obstruction."

"For clarification, the arrestee had passed through the metal detector area to the most secure area of the event accessible only to ticket holders. Whether she had a ticket or not for the event is not a contributing factor for the Tulsa Police in making the arrest," read the statement. "Officers at the location, particularly in the 'Sterile' area, will remove individuals only at the direction of Campaign Staff."

Earlier in the day, Tulsa police wrote on Twitter that there are "hundreds of officers" on duty in the city on Saturday, and that they expected it to be a "long and eventful day."

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"We need many voices against racism and against brutality," the Republican senator told a reporter during the demonstration

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Exacerbating public health concerns, the Trump campaign announced that six staffers who helped set up Saturday's rally have tested positive for COVID-19, according to the Associated Press. Tim Murtaugh, the campaign’s communications director, said "quarantine procedures" were followed, and the sick employees will not attend the event.

Rally attendees will have their temperatures checked before entering, and they will also be given masks and hand sanitizer for the large indoor event.

According to USA Today, the atmosphere surrounding the event early in the day was "celebratory," with Trump supporters proudly swaying American flags and holding up Trump 2020 signs, though many were without face coverings.