Wyndham Lathem, 42, an associate professor of microbiology at Northwestern, turned himself in at the Oakland, Calif., federal courthouse reports The Chicago Tribune, citing the U.S. Marshals Service. Andrew Warren, 56, a treasury assistant at Oxford University in Britain, surrendered to cops in San Francisco in connection with the death of Trenton Cornell-Duranleau, 26, who was found dead in Lathem's apartment on July 27.
Lathem and Warren are facing first-degree murder charges.
The attack was so violent that the blade of the knife believed to have been used to kill Cornell-Duranleau was broken, Guglielmi said.
Guglielmi said Lathem, an associate professor of microbiology-immunology at Northwestern University, had some kind of relationship with Cornell-Duranleau, who moved to Chicago from MI to work in a salon, but the two had "some type of falling out" before the fatal stabbing.
Warren was arrested in San Francisco while Lathem was arrested in Oakland, US Marshals inspector Ed Farrel told the Chicago Tribune.
Lathem joined the Northwestern faculty in 2007 and researched bacteria that cause disease in humans, particularly lung infections, according to his university biography page, which has since been removed.
He said: "We were not in contact with them directly".
He said that once police had "suspicions that the professor and his associate may have fled the Chicago area", several federal agencies were brought in to investigate and a national alert was sent to police departments across the country advising that murder warrants were issued for both men.
A spokesman for the university said that he had been banned from the campus and placed on administrative leave.
Speaking with USA Today, Mr Guglielmi said: "Police arrived at Lathem's apartment shortly after an employee at the building's front desk notified authorities of an anonymous call about a crime in the professor's apartment".
"We are also thankful both men are safely in custody and this did not end in further tragedy".
A hairstylist fondly recalled Cornell-Duranleau. Both Lathem and Warren are being held on no bond status.
"There is no indication of any risk to the Northwestern community from this individual at this time".
Police said that on the day of the slaying, but before the body had been discovered, Lathem and Warren drove about 80 miles northwest to Lake Geneva, Wisconsin.
"This is now a criminal matter under investigation by the appropriate authorities, and Northwestern University is cooperating in that investigation".