It happened late at night in front of a busy pizza parlor and bars, when students were out in costumes, drinking and partying in celebration of Halloween. When the police arrived shortly after 2 a.m. on Sunday, Hussain Saeed Alnahdi was already unconscious. He was bleeding from the nose and mouth, and his alleged attacker had fled the scene on foot.

Alnahdi, a gregarious 24-year-old junior at the University of Wisconsin-Stout, wasn’t alone when it happened. Less than an hour before, he had been hanging out with friends at a bar across the street, one friend said. The assault occurred on a crowded sidewalk. There were witnesses, police said. And there were nearby properties with security cameras.

But three days after Alnahdi died of his injuries, and the police force launched a homicide investigation, authorities have yet to identify a suspect or provide any further details about what transpired that night.

“We’re still in the course of the investigation,” said Todd Swartz, the local police department’s commander of operations in Menomonie, Wis.

The fatal encounter in Menomonie — population 16,200 — comes in the final days of a volatile and racially charged presidential race — in which Republican candidate Donald Trump has repeatedly condemned Muslims — and amid an ongoing spike in threats, attacks and harassment targeting Muslims and Arabs across the nation.

Alnahdi, a Saudi national who arrived in Menomonie to study at the university last year, is both Muslim and Arab. And in the aftermath of his death, allegations of a hate crime surged on social media, with some outside commentators referring to the young man’s anonymous attacker as an “American terrorist” born of Trump’s anti-Muslim rhetoric, while others declared Alnahdi had been brutally “beaten.”

“Don’t tell me Trump’s hateful rhetoric are ‘just words,’” tweeted Khaled Beydoun, a professor at Detroit Mercy Law School.

Swartz said Thursday that Menomonie police had not yet determined the motive in Alnahdi’s killing, and were not yet able to say whether it was a hate crime. Police were also unwilling to say whether the assault was preceded by a fight; whether Alnahdi had experienced previous altercations; or even how he died.

“I can’t comment on that,” Swartz said, when asked if Alnahdi was struck with an object.

“I don’t want to comment on that,” he said, when asked what the 6-foot-tall white male suspect police had initially described was wearing at the time.

Swartz said police were still interviewing witnesses and reviewing videos; still trying to confirm accounts. “We have to be cautious,” he said. Some witnesses might have been drunk. Others might not have had a clear view of the crime, he said. “We don’t want to put something out there that we haven’t confirmed yet.”

‘He immediately became like family’

Hussain Alnahdi was outgoing, and well-liked, even though he had been at the university for less than a year and a half.

“I never met a single person who didn’t like Hussain or didn’t instantly fall in love with his character,” said Zion Guzman, one of Alnahdi’s roommates.

Alnahdi had landed in a house with Guzman and a few of his friends the year before, largely by chance — “We had an open room in our house that our landlord filled, and it turned out to be a Saudi Arabian foreign exchange student,” he said.

Alnahdi knew little English when he arrived, but he quickly immersed himself in American culture. He asked questions and learned his roommates’ English slang. He visited their Wisconsin home towns, got to know their families, and wondered about the widespread popularity of cheese. In Menomonie, he was always giving out hugs, giggling and preparing huge Saudi meals for everyone, his friends said.

“He immediately became like family,” Guzman said.

But Guzman and other friends said they also didn’t want to talk about what happened on the night that Alnahdi was fatally wounded. One privately said they didn’t want to interfere in the investigation.

“At this time, we’re not going to talk about the incident or what happened at the hospital after,” Guzman said.

At 142 students in an overall student body of 9,616, Saudis make up the largest proportion of UW-Stout’s international students.

Many come to study engineering, technology or business administration through a partnership program, launched in 2012, between the university and a Saudi community college. But some also come on word of mouth, said Michael Lee, of the university’s Office of International Education. “The students really had great experiences and invited many of their friends and family to transfer from Saudi Arabia,” he said.

“Hussain reported to his family that he felt very safe here. That’s why he was self-supported,” Lee said.

Episodes of anti-Muslim harassment have flared nearby. Seventy miles away at the University of Minnesota on Thursday, vandals scrawled the word “ISIS” on the Muslim Student Association’s sign. And last month, in Lonsdale, Minn., a store owner put up a sign outside that read “Muslims get out” — under the store’s advertisement for ice cream; In Iowa, someone spray-painted Trump’s name in red letters on the side of a mosque.

Jaylani Hussein, the head of the Council on American-Islamic Relations’ Minnesota office, said he met with a number of Muslim students in Menomonie after Alnahdi’s death, and some of them reported being taunted in recent months.

“There has been a rise in tension, and some name-calling and harassment has been happening in the community,” he said.

Latinos had also experienced harassment, Hussein said, and some students wondered if Alnahdi—who with his dark hair, and light brown skin — “may have potentially been targeted for that.”

But if Menomonie has succumbed to the racial tensions and anti-Muslim prejudice that has appeared in other towns across the country, UW’s administrators, the town’s police force and many students said they were unaware of it.

“That’s what was really shocking about this. We wouldn’t see the influx of Saudi students that we’ve had if there had been any history of that,” Lee said Thursday, a few hours before students and faculty gathered on campus to pay an emotional tribute to Alnahdi.

“Menomonie community was safe,” said Abdirahman Kadi, another Saudi and the president of the school’s Muslim Students Association. “We have a lot of friends.”