University lecturer's killer locked flat from the inside

A neighbour of Roger Gray revealed he had a key to the dead man's home, but could not get in after smelling gas.

Bill Coventry said Mr Gray's Merchiston flat had been locked from the inside like "Fort Knox".

There has been speculation that the gas supply was tampered with and the attacker rigged up a gas explosion to destroy the crime scene. Locking the door from the inside would have given the flames more time to take hold and the attacker would have had to exit through a window.

Mr Coventry also revealed that this is not the first tragedy to hit Mr Gray's family. His elder brother committed suicide on a train line in the city.

And his sister died a few months ago, it is believed of natural causes.

Detectives have confirmed that Mr Gray, a 64-year-old Heriot Watt lecturer, was stabbed in a "sustained attack" at his Merchiston Crescent flat.

Mr Coventry, 77, who lives in the flat above Mr Gray, raised the alarm on Saturday morning when he smelled gas from his bedroom.

He said he had a key to his neighbour's flat as a result of an earlier flooding incident.

"We were a very harmonious kind of house where we all help each other. I had a key to Roger's flat because of a flood and because he didn't have any family," he said.

But on the morning of Mr Gray's death he was unable to get into the flat.

He said: "I couldn't get into his flat. It was locked from the inside because it was like Fort Knox. I'm glad I didn't get in because it was full of gas and also he was there."

It is understood police are investigating whether the attack on Mr Gray had anything to do with him being gay.

Mr Coventry said: "He was just himself. He never said he was gay, but he was. I mean everybody knew he was. But I mean he was courteous, he was a very intelligent man.

"He was utterly courteous and polite."

He added: "I didn't go to all of Roger's dos. I was at a party for his 64th birthday. They were informal and they were mostly Heriot-Watt faculty.

"There was a mixture of gay and straight people at them and they were all very nice people."

Mr Coventry said he was not aware of a "regular person" in his friend's life.

He said: "There was a friend of his who was a surgeon and I met him several times. But I haven't seen him for ages."

Mr Gray's elder brother, William Morris Gray, died on a railway line near Stanley Place, Edinburgh, in 1987, aged 46.

His sister, Sheila McNaughton McAra, a former school teacher from Edinburgh and believed to be in her early 70s, died last October.

A spokesman for Lothian and Borders Police said the death of Mr Gray was still being treated as suspicious.