The arrest of an Oxford University employee who was hunted by police across the United States 'avoided further tragedy'.

Somerville College senior treasury assistant Andrew Warren was believed to be on the run with Professor Wyndham Lathem, 42, from Northwestern University in Illinois.

The pair were wanted by police in connection with the murder of Trenton Cornell-Duranleau, 26, who was found dead with multiple stab wounds in Lathem's apartment in Chicago on July 27.

The pair gave themselves up to police on Friday evening at separate sites in California, more than 2,000 miles from the crime scene.

Oxford Mail:

Wanted: Andrew Warren, Oxford University employee. Picture: PA/Chicago Police Department

Chicago Police said officers were relieved to hear of the peaceful surrenders after fears grew when Lathem sent a video to family and friends apologising for his role in the murder.

Police spokesman Anthony Guglielmi said: "Once we got word that Dr Lathem had sent that video to friends and family we began getting concerned that perhaps he would harm himself or this could end up more tragically for both of them, so we are relieved that both of them are safe."

He said the victim and Lathem had been in a "personal relationship" and detectives believe the attack was domestically-motivated, but their connection to Warren is less clear.

Warren, who was dealing with "personal hardships", had been reported missing from the UK days before the attack and was not on Oxford business, he said.

But Mr Guglielmi added that detectives have unearthed some "online material" that suggests they met on the internet.

They separated at an unknown point as they travelled the US in a "vehicle" before Warren handed himself into a police station in San Francisco and Lathem gave himself up in Oakland.

He added: "Everything was peaceful.

"Andrew Warren walked into a police station and just said simply, 'I'm Andrew Warren, I'm wanted' and they took him right away."

It is not yet known whether their surrenders were co-ordinated and Supervisory Deputy US Marshal Frank Conroy said Lathem's came after lengthy negotiations though his friends and a lawyer.

Warren and Lathem now face extradition hearings to determine whether they can be sent to Chicago for questioning.