It was 11:30 p.m. Thursday, and the Columbia University senior had just left his late-night Afro-beats dance practice. He had work to do, and his anthropology thesis was looming, so the 23-year-old pulled out his phone to check a Facebook page where students can post and find the most universally reliable staple on American college campuses: free food.
Other students had just deposited party leftovers in the nearby Barnard College library, where Columbia students are welcome to study. McNab headed that way.
By the end of the night, he would find himself as the latest, forced subject of another viral video - the kind that has dominated the past decade by commanding outrage and reviving, all over again, the tense conversation communities are having nationwide about police use of force, racial profiling and the risks that come with being a person of color in America.
On his quest for free food, McNab had an encounter with police, which included a disagreement about his student ID that led officers to forcefully pin him to a countertop. The altercation, filmed by two witnesses, inspired a weekend of unrest at the Columbia and Barnard campuses, where administrators have released statements and held listening sessions and students have called attention to what some consider a chronic problem within the public safety department.
Barnard has issued two statements and hired an independent investigator.
The officers involved have been placed on paid administrative leave.
McNab, who said all he wanted to do was work and study this weekend, has instead spent it fielding interviews, answering emails and explaining what it's like to be black.
"There's never a good time for this to happen," McNab told The Washington Post. "But this weekend, I had all these things to do."
The night of the encounter, McNab said he set off into the night toward the free food, crossing the street dividing the Columbia and Barnard campuses and passing in front of a Barnard public safety van waiting to turn left. McNab said he sped up as he crossed, wanting to catch the light before it expired.
He walked through the official gate to Barnard's campus, where he heard someone shout: "Hello, sir! Hello, sir!"
He didn't look back - not this time.
McNab thought about the two other occasions he had been stopped by Barnard officers and asked to show his ID, encounters he believes were a result of racial profiling. They once demanded to see his ID as he was leaving a two-hour dance practice. Another time, he left dance practice to run to the bathroom - barefoot - and he was stopped again because the officers thought he was homeless.
It's campus policy to ask for student identification after 11 p.m., a rule McNab later said he was aware of but had not thought about in the moment. At the time, he said he believed the officers were only stopping him because of his skin color.
McNab kept walking, into the library and toward the food. The female students greeted him, offered him a plate and told him to take as much as he wanted. He scooped up some rice and lamb. Then the officers walked in.
There were two of them, then four, then more. They demanded to see McNab's student ID, he and witnesses say, and grabbed McNab's arms. The officers pushed him against the register counter at the coffee shop on the library's first floor. They forced him onto his back.
That's when Caroline Cutlip, a Barnard junior who had posted about the free food in the first place, started filming.
"The moment I saw him pinned back on the table, it was so reminiscent of police brutality things I've seen online," Cutlip, the only white student watching, later said of her decision. She said she thought to herself: "I need to say something. I feel like I am someone who can use my privilege to say something here."
"But I had no clue what to say," Cutlip said. "So I started filming."
In the first of two videos she recorded, McNab is surrounded by at least five public safety officers.
"Take your hands off me!" McNab yelled as the officers immobilize him.
They demanded to see his student ID card. One officer glanced over his shoulder toward the table of Barnard students where Cutlip was filming. The officer looked back at McNab, then again toward Cutlip's camera. He released his grip.
"OK, let's walk outside," the officer said.
With his hands free, McNab pulled his wallet from the front pocket of his pants.
"You want to see my ID?" he said, handing them his card. "I am a Columbia University student. That's me. This is the third time Barnard Public Safety has chased me down."
An officer took McNab's ID card and began to walk outside, again commanding that McNab follow. McNab refused, explaining later to The Post that he wanted to stay near witnesses. He was afraid that leaving the building would jeopardize his safety.
In the video, McNab is seen waiting by the Barnard students. He murmurs an apology, and a student firmly responds: "No, don't be sorry."
The officer says he is going to confirm that McNab is an "active student," and he returns with the student's ID card.
Cutlip began filming a second video, this one showing the officers telling McNab that he ran into the building without showing his ID. McNab says he walked, not ran, and the Barnard students back him up.
"I got him running through the courtyard," the lead officer says.
At the same time, a second officer begins arguing with the Barnard students, saying McNab ran in front of his van. McNab and the other students refute that narrative again, and the second officer raises his voice at a black female student.
"Do you have a gauge that you can measure how fast he was running?" the officer asked her.
"Does it matter?" she responded.
"Were you there?" he said back, walking closer, pointing his finger and eventually telling her to "relax."
In unison, the other Barnard students repeated the word "relax" with exasperation.
"I am relaxed," she said.
"Yeah, well I don't see that," the officer said. "Right away, you're taking a . . ."
"Please stop talking to me," she said.
The officer walked away, the video cut off and eventually McNab and the Barnard students were alone again in the library, left to rehash what had happened.
Several of the Barnard students were crying.
"It showed me that this wasn't just something I went through," McNab told The Post. "They went through this, too."
McNab said another student suggested the incident was worthy of a complaint to Barnard's Title IX officer, so she sent one.
Cutlip, a student government representative, had met that morning with the Title IX officer and later worked with her and other student government members to craft an official statement. In the afternoon, Cutlip posted her videos online.
By Friday afternoon, Barnard's president, Sian Leah Beilock, released a statement to students and staffers about the "unfortunate incident" at the library, but it did not outline any details.
"We deeply regret that this incident occurred, and we are undertaking a thorough review of our public safety officers' actions, and will address our processes and procedures and how they are applied," the statement said.
Beilock also announced a listening session for Friday evening with public safety officials and members of the Barnard administration.
McNab watched as his peers scrutinized the language Barnard officials used to talk about the "incident," listened to them call him "the student" and grew disappointed when the administration, in his eyes, didn't squarely confront the racial elements of his experience.
He said at the event that he would "appreciate an apology."
Several administrators repeated the language of the email - that they regret the incident - and used the phrase "we apologize."
"Why can't you call it racism?" a student asked.
What McNab said he was looking for, though, came from one Barnard administrator, Dean of Studies Natalie J. Friedman, who welcomed him to campus and thank him for speaking.
"I also apologize on behalf of the college," she said, "for the racist incident that happened."
McNab walked up and shook her hand.
"To me, that was the most beautiful thing she could do," he later said.
In the days since, administrators from Columbia have released their own statements and several of McNab's anthropology professors have reached out in support.
"I've been trying to figure out the right vocabulary to use," McNab said Sunday morning, as he prepared his to-do list.
There was his job as a tutor, a paper for one class and a couple of articles for student publications.
And there was protest spurred by his altercation. He wanted to go, he said, but "I was supposed to finish my thesis this weekend."
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)