Erin Tanti, above, is denying charges of murdering and assisting his 15-year-old drama student Lisa Marie Zahra, top, to commit suicide.

A three-dimensional model of Dingli Cliffs, where 15-year-old Lisa Marie Zahra died, showed her teacher Erin Tanti was found 42 metres away from her body.

The model, created by criminologist Saviour Formosa, marked the 32-metre “drop point” on the cliffs from which Ms Zahra is believed to have fallen. It also marked the areas where rescuers found Ms Zahra and Mr Tanti.

This was the first time such a model had been presented in court as evidence.

It was exhibited before Magistrate Audrey Demicoli during the compilation of evidence against Mr Tanti, who is pleading not guilty to murdering his 15-year-old drama student and assisting her to commit suicide on the cliffs on March 19.

He is also charged with defiling her, participating in sexual acts and being in possession of indecent images of her.

Dr Formosa said he had been nominated by the court to carry out a spatial analysis of the area.

He studied the location in which Ms Zahra and Mr Tanti were found, including distances and geographical elements. This was based on photos of the location given to him by police and site visits he carried out.

He created the model with spatial mapping technology and marked the presumed drop point based on mathematical calculations.

Testifying in a previous court sitting, Police Sergeant Conrad Debattista said that Mr Tanti had told police how he and Ms Zahra jumped together at about 3am. Surviving the fall, he tried to find another way to kill himself and dragged himself across the rocks.

Yesterday, the court also heard Glen Zarb and Brendon Cutajar recount that on March 19 at about 10am, they met with a group of friends in Dingli for a barbecue.

As they headed back at about 4pm, they heard distant, urgent shouts of “Hey” or “Help” and realised someone was in trouble.

The person seemed to be about 100 metres away, lying on the grass, unable to move and in an area they could not access.

Lawyers Michael and Lucio Sciriha are representing Mr Tanti, while lawyers Giannella de Marco and Joseph Giglio are representing the Zahra family. Police Inspectors Keith Arnaud, Sylvana Briffa and Josric Mifsud are prosecuting.