A hard-luck hairstylist found dead in a swank downtown high-rise. A Chicago professor renowned for his research on the plague, on the run with an unassuming payroll clerk from a British university.

If the story of killing of Trenton H. James Cornell-Duranleau and the flight of Northwestern microbiologist Wyndham Lathem and Oxford College bursar Andrew Warren seems strange to those reading about it in the news, the tale is stranger still to those who knew the three men now linked by a bloody murder scene 10 stories above North State Street.

“We’re all in a complete state of shock,” said William Goldman, a microbiologist at University of North Carolina who supervised Lathem when Lathem was a post-doctoral researcher at Washington University. “I keep thinking there has to be some other explanation . . .  There’s just nothing that would have led me to predict something like this.”

Lathem, 42, surrendered Friday night at the Oakland federal building at around the same time that Warren, 56, was turning himself in to police in San Francisco, according to Michael McCloud, a fugitive task force commander with the U.S. Marshals Service.

The two are expected to appear in court in California on Monday, then will be extradited to Chicago.

Their apprehension came after Lathem sent an “apologetic” video to friends and family using encryption software – and after he and Warren made a $1,000 donation to the public library in Lake Geneva, Wisconsin, in honor of Cornell-Duranleau.

Trenton H. James Cornell-Duranleau

Lathem had a string of impressive research publications since joining the faculty at Northwestern’s Feinberg School of Medicine in 2007 and was widely respected in his field, Goldberg said.

Lathem’s expertise was in the study of mutations that allow pathogens to become especially deadly, and he had done extensive research into bacteria that caused the Black Plague. Lathem was fascinated by the plague’s impact on human health, but also on 14th Century society and culture.

Despite the subject matter, disease researchers are hardly a dark or dangerous bunch, Goldman said.

“There’s so many of us that work on really dreadful diseases,” he said. “They’re all perfectly normal people.”

Cornell-Duranleau’s life story was more troubled. After he lost his job and ended up homeless in a Michigan motel, Cornell-Duranleau moved to Chicago early in the spring of 2016 to live with Zak Singer — who said the two met on a dating app.

Singer said he and Cornell-Duranleau lived together in an apartment in Rogers Park. In an instant message conversation with the Sun-Times, Singer said 26-year-old Cornell-Duranleau was outspoken with a “fiery” temper.

Cornell-Duranleau moved out of the apartment in early May 2016, which was the last time Singer talked to him. Cornell-Duranleau’s Michigan cosmetology license didn’t transfer to Illinois, so he cut people’s hair in his apartment for cash and later worked at a Starbucks downtown. He had dreams of becoming a veterinary tech, and in an obituary posted on Facebook, family members recalled his love of animals.

Singer knew that Cornell-Duranleau had bounced around the city, until he was fatally stabbed July 27 in Lathem’s River North apartment. The Cook County Medical Examiner listed Cornell-Duranleau’s address as an apartment building in the Heart of Chicago neighborhood, but police said he lived with Lathem, 42.

Singer said he was shocked when he learned of Cornell-Duranleau’s death from a mutual friend.

“It’s horrific news,” he said. “He was an ultimately good but struggling person. No one that has talked to me about it is in good spirits.”

After seeing media reports about Lathem, Singer said a few of his friends realized they had met up Lathem in the past through dating apps and thought he was “unnerving.”

“I got the impression that he just creeped people out,” Singer said. “I didn’t learn specific reasoning behind people’s reaction to him — more that they wouldn’t see him again when he tried to suggest another date.”

Cornell-Duranleau made friends easily, said Singer, and was curious and enthusiastic about life. He loved to sing pop and country music, and was a huge fan of Adam Lambert and Lady Gaga. But he also could be defensive.

“He was trying to figure out his footing here, including finding a partner and a place to live,” said another friend who asked to remain anonymous.

As a child, Cornell-Duranleau struggled. He told Singer about his difficult past: his mother committed suicide when he was very young; he had never met his father, who was in prison. After his mother died, he went into foster care and bounced around until he was adopted by Mischelle Duranleau and Charlotte Cornell, a same-sex couple living in a small town in Michigan.

“He had told me he didn’t find a family that fit him well until his teens,” Singer said.

In an obituary posted on her Facebook page, his mother, Mischelle Duranleau, said he was born in the small town of Lennon, Mich.  Cornell-Duranleau was raised among a large family of adopted siblings.

He was “very creative and visually inspired by everyday objects,” Singer said.

“He liked to tinker around with random things, fixing, building, reconstructing just about anything he could get his hands on,” he said.

Warren’s relatives in England had reported to police in England that he had gone missing on July 25, two days before Cornell-Duranleau was found dead of multiple stab wounds and his genitals mutilated inside the Grand Plaza tower apartment.

Warren, 56, left behind his boyfriend and sister, making his first trip to the U.S. without telling anyone, the London Telegraph reported. Police initially told the family Warren was in Spain. A former bus driver who worked in payroll for Oxford’s Somerville College, Warren had been depressed since the death of his father eight months ago.

Goldman said Lathem was well-traveled and spoke fluent French. Internationally known for his research, Lathem had recently considered taking a position at the Pasteur Institute in France, Goldman said. Despite his research brilliance and global connections, Goldman said he couldn’t picture whether his former post-doc might grow desperate or spend months – or years – evading authorities, Goldman said.

“The whole concept is so alien to everything I know about him,” he said. “I don’t understand what’s going on, so its very hard for me to try to predict what comes next.”