A FORMER forensic scientist told a murder retrial she “must have missed” a bloodstain which prosecutors say proves the accused’s guilt.

Catherine Miller examined Mark Weston’s boots while working for the Government’s Forensic Science Service after the August 1995 killing of Vikki Thompson in Ascott-under-Wychwood.

She told jurors at Reading Crown Court she rubbed filter paper on the boots and then chemically analysed the paper, but could not remember using a microscope or magnifying glass.

But 2008 and 2009 analysis found bloodstains which prosecutors say contain Mrs Thompson’s blood.

Mrs Miller said: “I must have missed the blood. That’s the only explanation.”

Mrs Thompson, 30, was found by a railway embankment with head wounds and died six days later.

Pauline Stevens, of LGC Forensics, who recently examined the boots, said one stain was visible under a microscope.

They spent four days examining the boots, jurors heard.

She said of a larger stain: “I would have been disappointed if I hadn’t found that bloodstain.”

Some of the blood was Mrs Thompson’s, she said.

Weston, of Dawls Close in the village, denies murder. The trial continues.