Story highlights Killing not "domestic in nature," detective says; "It was a little bit more dark and disturbing"

Both suspects held without bond after judge hears sex fantasy allegations, affiliate reports

(CNN) Police have formally charged a former Northwestern University professor and an Oxford University employee with first-degree murder in the July stabbing death of a 26-year-old cosmetologist, Chicago police and the US Marshals Service said Sunday.

Ex-professor Wyndham Lathem and Andrew Warren were extradited Friday to Chicago from Northern California after their arrests earlier this month in what Chicago Police Superintendent Eddie Johnson called the "savage and grisly" killing of Trenton Cornell-Duranleau.

After the killing, US marshals tracked the men from Chicago to Wisconsin to California before negotiating their surrenders through an attorney, US Marshal Donal McCarthy said.

Lathem was arrested in Oakland, and Warren turned himself in in San Francisco, the marshal said.

"What I can tell you, it was not domestic in nature -- like a husband/wife or boyfriend/boyfriend or love triangle -- that was not the motive. It was a little bit more dark and disturbing," Chicago police Detective Cmdr. Brendan Deenihan told reporters.

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