Wyndham Lathem, 42, and Andrew Warren, 56, are both considered armed and dangerous. They are wanted for first degree murder in connection with the stabbing death of 26-year-old Trenton Cornell-Duranleau.
They were last seen driving a 2007 grey Hyundai passenger 4-door vehicle with the Illinois license plate number of Z181268. Anyone who has seen the car or suspects should take extreme caution and either call 911 or Area Central Detectives at (312) 747-8380.
Cornell-Duranleau was found stabbed to death last Thursday in the Grand Plaza Apartments on State Street in the city's affluent River North neighborhood.
The 10th floor unit belongs to Lathem, who was an associate professor of microbiology and immunology at Northwestern University's Feinberg School of Medicine. He worked primarily in research labs and gave lectures.
"There's shock, there's no doubt about it. You know, this place is very safe. I've been here 14 years and I've never heard of problems such as that," said Richard Aili, Grand Plaza Apartments resident.
Cornell-Duranleau's body was discovered after police responded to an anonymous call that a crime had been committed in a 10th floor unit.
Cornell-Duranleau had lived in the city's Pilsen neighborhood for just a few months, neighbors said. Originally from Michigan, he was a licensed cosmetologist.
"I started noticing him about a year ago," said neighbor Marco Arce. "I didn't know him, but yeah, I always told him, 'Be safe, be careful.' And then I'd just go back in my house and that's it."
Neighbors also said they had seen Lathem in the neighborhood before.
Police have not released a possible motive or said how they linked the suspects to the killing, but Chicago police spokesman Anthony Guglielmi said security camera footage shows them leaving the building that night.
Guglielmi said Lathem and Cornell-Duranleau knew each other, but he didn't know any details about the relationship. He said investigators determined that Warren, who lives in England, came to the U.S. recently for the first time, but he didn't know if Warren knew the victim.
Aili said building management sent out an email after the incident saying that, "Police are currently working on the timeline and background of the victim and are exploring a variety of motives, including a possible domestic incident."
Northwestern issued a statement saying Lathem, who has worked at the university for 10 years, "...has been placed on administrative leave and banned from entering the Northwestern University campuses."
Warren is a senior treasury assistant at the University of Oxford in Great Britain, according to the university's website.
A police all call went out Wednesday morning.
The Associated Press contributed to this report.