CHICAGO -- A Northwestern University professor and a University of Oxford employee wanted in the brutal stabbing death of a Chicago man surrendered peacefully in California and will be returned to Chicago for interrogation, federal and local authorities said.

Wyndham Lathem, 42, gave himself up late Friday at the Oakland federal building and Andrew Warren, 56, surrendered at about the same time to the San Francisco Police Department, according to Michael McCloud, fugitive taskforce commander with the U.S. Marshals Service.

Their capture was announced Friday night by Chicago police spokesman Anthony Guglielmi, who credited the U.S. Marshals Service with handing the suspects over to California police, CBS Chicago reports.

Get Breaking News Delivered to Your Inbox

McCloud said the surrender of the two suspects was "negotiated," although he declined to say how that happened.

"We were not in contact with them directly," during the negotiations, he said.

Lathem, an associate microbiology professor at Northwestern, was booked into the Alameda County jail. Warren, a Somerville College resident at Oxford University in England, was taken to the San Francisco County Jail. They will appear separately in court before being extradited to Illinois. It was not immediately clear when that would happen.

A manhunt had been underway since shortly after the body of 26-year-old Trenton James Cornell-Duranleau was found riddled with stab wounds on July 27 in the Chicago apartment where Lathem lived.

"Both individuals will be held accountable for their actions and we hope today's arrest brings some comfort for the victim's family," a Chicago police statement said.

Police said Lathem had sent a video to friends and relatives apologizing for his involvement in the crime, which he called the "biggest mistake of my life." The video raised concern among investigators that Lathem might kill himself.

Police said earlier on Friday that Lathem had sent a video to friends and relatives apologizing for his involvement in a crime that he called the "biggest mistake of my life," raising concern among investigators that he might kill himself. Warren had arrived in the United States three days before the death of Cornell-Duranleau and was seen in surveillance video leaving the building with Lathem that day.

"We are also thankful both men are safely in custody and this did not end in further tragedy," the police statement said.

Warren had arrived in the United States three days before the death of Cornell-Duranleau and was seen in surveillance video leaving the building with Lathem the day of the stabbing.

McCloud said the U.S. Marshals Service learned on Wednesday that the two men might be in the San Francisco Bay area. About noon Friday, he said they received further information that they were still in the area. The suspects both surrendered at about 7:30 p.m. local time, he said.

Police said Lathem had a personal relationship with Cornell-Duranleau, who moved to Chicago from the Grand Rapids, Michigan, area after receiving his cosmetology license. They are not sure how Cornell-Duranleau or Lathem knew Warren, or if Warren knew them before he flew to the United States before the stabbing.

In a bizarre twist, 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, where one of them made a $1,000 cash donation to the public library there in Cornell-Duranleau's name. Lake Geneva police said the man making the donation did not give his name.

"I've never seen where suspects in a homicide would make a donation in the victim's name," said Lake Geneva police Lt. Edward Gritzner.

On the night of the slaying, police said the front desk of the high-rise building where Lathem lived in Chicago's trendy River North neighborhood received an anonymous call from a person who said that a crime had been committed in Lathem's 10th floor apartment. When police opened the door they found Cornell-Duranleau's body. He had been stabbed several times in an attack so brutal that police said the knife broke.

Police also said that by the time they found the body on the night of July 27, Cornell-Duranleau had been dead for 12-15 hours.