Detective who led inquiry says others may have been involved in 2008 double murder

A man convicted of murdering two Chinese students in Newcastle 10 years ago may not have acted alone, according to the detective who led the investigation.

Xi Zhou and Zhen Xing Yang, both 25, were found dead in their ground-floor flat in Arthur’s Hill on 9 August 2008.

The couple, known as Cici and Kevin, had been bound with tape and beaten with a hammer. Yang’s throat had been cut and his skull smashed in, and Zhou had been forcibly gagged and her skull fractured. Their cat was found drowned in the flat.

Guang Hui Cao was convicted of the double murder a year later at Newcastle crown court and jailed for a minimum of 33 years.

On the 10th anniversary of the killing, the senior investigating officer, Steve Wade, now retired, has raised his long-held concerns that the convicted killer did not act alone.

He told the Chronicle: “I wouldn’t be surprised if someone else was involved. It was a very unusual crime in itself – tying two people up with tape. We were happy through the forensic evidence that it happened before death. How do you do that when you are on your own?”

Wade believes the killings were related to an organised crime network and conspirators may not have been brought to justice.

The investigation revealed that Zhou and Yang were involved in a betting scam and the production of false qualifications to secure places at university. The trial heard they had a declared income of £17,000 a year, mostly from Zhou’s waitressing job, but more than £233,000 had passed through their bank account.

Cao was living in Morpeth and had been dodging immigration checks for five years at the time he was arrested. He admitted in court he had been in the flat at the time of the killings but said he too had been tied up by people who had blackmailed him into applying for a spare room the couple were letting.

Although this defence was rejected by the jury, the judge agreed with the police that the victims could have “in some way crossed those involved in organising their criminal activities”.

Wade said: “What we have never understood is how or why that level of violence was used. It wasn’t like these people were gangsters; they were two kids. It was possibly a lesson was being sent out to anyone else involved in that, but we could never say for sure that’s why they were killed.

“Whilst there was no other DNA evidence in that house and there was nobody else convicted, and to all intents and purposes he did it by himself, it always left us wondering: was he alone when he did that crime?”

During the original investigation an estimated half a billion people tuned in to coverage of a briefing for Chinese media in London – an event held to try to assure Chinese people that the police were carrying out a thorough investigation.

Yang’s mother, Shu Zhen Qu, came to Newcastle for the trial and spoke of her grief. “This person did not just kill two people, he has killed two families,” she said. “We have now been sentenced to go to hell. Our family will never be able to have any future generations.”