The jury in the trial of two teenagers accused of murdering Farnham schoolboy Luis Guembes has been shown new measurements of the Guildford park where he was fatally stabbed.

Lauren Sargent, of Surrey Police, was recalled to the witness box on Thursday (October 29) to explain measurements taken in the Wildwood area of Stoke Park, where Luis and Defendant 2 were last seen together on CCTV.

Ms Sargent had returned to the park with two crime investigators following her evidence last week to measure distances between locations relevant to the case.

The jury was shown photographs and diagrams identifying the approximate location where the pair were last seen, places where blood associated with Luis was found, steps leading to a zip wire and the position of first responders.

Photographs taken at different times were also presented to illustrate the steps and paths leading into the surrounding woodland.

The measurements were used to help jurors understand the layout of the area and the distances between the various locations.

The jury also heard further agreed facts concerning items recovered by police from one of the defendants' addresses.

These included an Honor mobile phone which, the court heard, was used by Defendant 1 during the relevant period.

The agreed facts referred to several video recordings, including a 47-second video recorded at 6.04pm on January 19 which appeared to have been deleted.

The recording included the words: “I [expletive] stabbed him bro.”

Further evidence was also heard concerning an ornamental-style knife.

An officer who carried out a Google image search found similar knives but no exact match. The court was told that a drawing made by a witness was a closer match than the knives found online.

Knives and ornamental materials were examined by Cellmark Services. The court heard that testing with damp pH paper produced neither an acidic nor an alkaline reaction.

Urban slang expert Rhys Marshall also gave evidence, explaining that the word “stain” meant to rob someone.

All Hallow Catholic School pupil Luis Guembes, 15, was fatally stabbed in Stoke Park, Guildford, on January 19 of this year. Two teenagers deny murdering him.

The trial continues.