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As is the case in so many of these horrific attacks, family members and friends never saw it coming. That’s the story for Somali refugee Abdul Artan, who injured 11 people during a rampage on the Ohio State University campus on Monday.

Artan crashed a relative’s car into a crowd of students and then began slashing at them with a butcher’s knife. A campus police officer shot and killed him.

ISIS claimed Artan was a “soldier” of their cause, and prior to the attack, Artan posted on Facebook that he had reached a “boiling point” over how Muslims are treated in the United States. However, if that is the case, his family members and friends say they didn’t see it.

“He was a sweet boy,” a family friend told “This is not anything that we teach our people. We are just as shocked as everyone else. His family are in mourning. They cannot understand how this horrible situation happened. It’s just so unexpected.”

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Hassan Omar, the director of the Ohio Somali Muslim Association told that Artan’s mother told him she is “devastated” by his actions.

“She was, as you can imagine, shocked that her son had done such a horrible act,” Omar said. “She cannot believe her son could kill, and she felt that she hardly knew her son at all because of it.”

Artan grew up in Somalia, but his family, including his mother and six siblings, fled to Pakistan in 2007. They made their way to the United States two years ago as refugees, landing in Columbus, Ohio, a city with a sizable Somali community.

Artan graduated from community college before enrolling at Ohio State in the fall.

Omar urged that people view this as an isolated incident. Also, he did worry that the attack could set off others.

President-elect Donald Trump, who set a hard-line stance against refugees from countries known to have terrorists during his campaign, has said that Artan and his family should not have been in the United States.

In a separate Facebook post, Artan hailed the al-Qaeda cleric Anwar al-Awlaki as a “hero.” Officials have yet to discover a direct tie to ISIS, but the group has seized on the attack and claimed responsibility via the jihadist-linked Amaq news agency.

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“The executor of the attack in the American state of Ohio is a soldier of the Islamic State,” the agency quoted an alleged ISIS agent as saying, according to a translation by the SITE monitoring group.

“He carried out the operation in response to calls to target citizens of international coalition countries.”

Neighbor Luann Carnahan said up to eight people lived in the small apartment near the Ohio State campus, and that their living conditions were cramped and dirty. She complained of visitors coming to the apartment at night and loud noises that would interfere with her children sleeping.

However, she said she saw no signs that Artan was capable of such an act.

“There was no indication he would do something like that, certainly by the way he presented himself, which was in a very dignified manner,” she said. “The FBI came to talk to me, and I’m not at liberty to share what we spoke about, but it’s just so scary to know that someone like that was living just next door. I don’t know why Abdul did what he did, and I saw what he put on Facebook, but that wasn’t the guy I knew, and that saddens my heart.”