"I am deeply sorry for what I did Saturday night. It was wrong and reckless. I made a horrible mistake by joining into the singing and encouraging others to do the same," Parker Rice said in a statement printed by the newspaper.
The decision comes two days after a video of frat members singing a racist song surfaced and hours after Boren told CNN he would suspend or expel the group's ringleaders if at all possible.
"At this point, all I can do is be thoughtful and prayerful about my next steps, but I am also concerned about the fraternity friends still on campus. Apparently, they are feeling unsafe and some have been harassed by others. Hopefully, the university will protect them," Rice reportedly said in his apology.
Already, the Greek letters sigma, alpha and epsilon have been removed from the frat house's facade, the house will be closed as of midnight Tuesday and the university will board up the windows, following up on separate decisions by the university and the SAE national headquarters to shutter the Oklahoma chapter, Boren said.
Rice has not responded to multiple requests from CNN for comment.
"For me, this is a devastating lesson and I am seeking guidance on how I can learn from this and make sure it never happens again. My goal for the long-term is to be a man who has the heart and the courage to reject racism wherever I see or experience it in the future," his apology read.
The video and its fallout
It was only a nine-second clip, but the backlash has been disastrous.
Party-bound students are seen on a bus clapping, pumping their fists and laughing as they chant
, "There will never be a ni**** SAE. You can hang him from a tree, but he can never sign with me. There will never be a ni**** SAE."
After the campus organization, Unheard, and the school newspaper received the clip via anonymous messages and publicized it, the university and the fraternity's national chapter acted swiftly to shutter the SAE house in Norman. Boren promised the university's affiliation with the fraternity was done.
"I was not only shocked and disappointed but disgusted by the outright display of racism displayed in the video," said Brad Cohen, the fraternity's national president
. "SAE is a diverse organization, and we have zero tolerance for racism or any bad behavior."
Still, it could get worse. Oklahoma may not be the only source of embarrassment for the fraternity.
"Several other incidents with chapters or members have been brought to the attention of the headquarters staff and leaders, and each of those instances will be investigated for further action," SAE said.
It's likely that if the university hadn't acted, the Department of Justice's Civil Rights Division could have stepped in, said Barbara Arnwine, president and executive director of the Lawyers' Committee for Civil Rights Under Law.
Title VI of the Civil Rights Act of 1964 "prohibits discrimination on the basis of race, color, and national origin in programs and activities receiving federal financial assistance," according to the Justice Department.
In this case, Arnwine said, the university likely found that fraternity members appear not only to have discriminated in their membership -- and backed that discrimination with the threat of lynching -- but they've also created a hostile environment.
The university, she said, "would've been compelled to do something to sanction and prevent this fraternity from engaging in racial discrimination."
Arnwine said she wasn't personally familiar with the school's code of conduct, but she'd be surprised if the fraternity members' actions weren't in violation of university rules as well.
All of these reasons are grounds to sanction the fraternity and expel specific members who were involved in the singing, she said.
"A very important part of the lexicon of civil rights law is that you cannot create a hostile environment where you make it so people of different races or religions or women feel they can't function at your institution without being subjected to unlawful discrimination," she said.
It's unclear whether more students will be punished for the video, though Boren has promised the SAEs won't return during his tenure if he can help it.
"The house will be closed, and as far as I'm concerned, they won't be back," he said at a Monday news conference.
He later told CNN, "There seems to be a culture in some of these fraternities, and it just has to be snuffed out."
The decision to shutter the fraternity was an easy one for Boren, he said.
"If we're ever going to snuff this out in the whole country, let alone on college campuses, we're going to have to have zero tolerance, and we have to act right away," said Boren, a former Oklahoma governor and U.S. senator. "This is not a place that wants racists or bigots on our campus or will tolerate it, so I think you have to send a very strong signal."
Hundreds of students have protested the fraternity's actions. Some of them arrived Monday morning on the campus' North Oval with tape over their mouths, while the Oklahoma football team and Coach Bob Stoops marched arm in arm across campus instead of practicing.
The video infuriated Oklahoma linebacker Eric Striker, who posted a profanity-laced video to social media.
"I was angry and I was outraged," Striker said. "I apologize for the profanity, but I'm not apologizing about how I felt, because that's how I felt in my heart."
The fallout from the video also cost the football team a top recruit as offensive lineman Jean Delance said Monday he was de-committing from the Sooners and considering other teams.
'That needed to happen'
Just as they protested loudly Monday, students on Tuesday were emphatic in expressing their relief and satisfaction that those allegedly responsible for leading the racist chant got their due.
Ross Johnson, a senior studying drama and broadcast media, called the video embarrassing and unacceptable as he worried that it may be seen as a reflection on him in the future.
"It sucks that I'm graduating in May. I feel I am probably going to have to explain this when I move," he said. "For people who don't know the University of Oklahoma, aren't part of the student body, it's a black eye that doesn't really deserve to be there. It's a small group of people who were acting foolishly."
Another student, junior Jake Hewitt, applauded the university and the fraternity's national president for their handling of the incident.
"I think it's really good that the president is showing strong support for the students in the community here and saying, 'This is not OK. It's not going to be acceptable on our campus.' It's a good strong move, and I hope if they find out more, they do more," he said.
Shortly after the expulsions were announced, senior Omar Humphrey, an African-American modern dance student, told CNN, "I think it's rightfully so that they were (kicked out). ... That needed to happen. It wasn't fair; it wasn't right. I am, as most of the student body -- not just the African-American students -- we're all disheartened by the situation. It's just really hard to think that this is still going on today, and I'm still deeply saddened."
He is still a "proud student," he said, and he understands that the fraternity members in question represent "just some microbial infestation that's on campus. It's on every campus, it's on every campus. It's unfortunate that we have to be seen in that light."
Asked what he could say to the fraternity members if given the chance, Humphrey replied, "I pray for their humanity. I hope that they find maturity. ... I wish them well. "
Unheard co-director Chelsea Davis said a racist mentality is not new to campus and is not confined to one fraternity.
"Unfortunately, it took them getting caught on video camera for this to happen, but this is definitely not something that is brand-new. It's not something that's only seen within this one organization," she said.
Davis said the only acceptable response is to expel -- not suspend, as that would send the wrong message -- all the students involved.
"I was hurt that my fellow peers that I walk to class with every day, people that I see every day, could say such hateful things about me and my culture, about my friends, about my brothers and my sisters," she said.
William Bruce James II, who was a member of the frat between 2001 and 2005, called the episode "devastating" -- not just because he's an Oklahoma alumnus but also because he's African-American.
James told CNN that there was "never an inkling of this song or a whisper of anything like this" when he lived in the house. He said members of his pledge class "wouldn't let that happen," and if someone did dare to start such a chant they'd swiftly speak out and shut it down "whether I was there or not."
Since the video surfaced, James said he's heard from many of his former fraternity brothers. Like him, they're offended and supportive of the decision to shutter the Norman chapter.
"I don't know what happened to the culture of my home," he said. "That is not my home. That is not SAE. They are not my brothers."