During the course of the trial, the experts of the scientific police and Dr. Pellero, defence consultant, presented their arguments to the Court on this issue.
The experts of the scientific police:
· formulated approximate hypotheses on the radio-electric coverage, displaying a map on which they reported the direction of radiation only of the cells engaged by the investigated phones and, in order to define the area served by these cells, traced ‘circles’ of position and radius without taking into account either the technical characteristics of the system of the telephone operator, or the orography of the territory, or any model of a scientific propagation, or the interaction of the neighbouring cells;
· only performed measurements on the field strength of the signals emitted by the cell phone network, without acquiring any of the elements transmitted by the network which condition the choice of cell involved, nor making reference to the selection criteria adopted by the cell phones;
· noted how, when carrying out field strength measurements:
a. even a movement of half a meter involves a significant change in the conditions of reception (p. 335 judgment);
b. the reception capacity of the cell phones is conditioned by the field strength of the signal transmitted by the cell, a strength which below -102 dBm renders the signal unusable for telecommunications (p. 335
judgment);
· carried out field strength measurements of the signal emitted by the cell phone network only in proximity to the places of investigative interest, as follows:
a. outside the building in Via della Pergola in the garden;
b. outside the building in Via della Pergola, in proximity to the window of Meredith Kercher’s room;
c. outside Raffaele Sollecito’s building;
d. in the garden of the building on Via Sperandio 5 bis.
Dr. Pellero, Sollecito’s defence consultant:
· acquired detailed data on the radio-electric coverage of the cells at the time of the crime directly from the source, the cell phone operators. This allowed it to be
demonstrated to the Court, on the basis of objective data, that the area of coverage of each cell is far from a regular geometric shape. Taking into account the technical characteristics of the systems, the orography of the territory and an appropriate model of scientific propagation, the telephone operator makes the area of coverage of each cell adopt the dimensions and the shape most able to serve its own customers, both in terms of quality and of density of traffic. This allowed the production of a detailed map, based on objective data which, also taking into account the interaction of all the cells present in the area of investigative interest, shows – with best approximation – the coverage area of each cell, or rather, the area within which, with maximum probability, the device which connected with each cell would be found;
· carried out field strength measurements of the signals emitted by the cell phone network, taking care to also acquire the elements transmitted by the cell phone network which condition the choice of which cell will be connected with, with reference to the selection criteria adopted by the cell phones (objective criteria fixed by binding Technical Regulations – ETSI Standards – knowledge of which was given to the Court, and which clearly indicate that the choice of cell is not solely a function of the field strength measured by the cell phone);
· carried out field strength measurements (including any incidental data) of the
interest, as follows:
a. outside the building on Via della Pergola, in the garden;
b. inside the building on Via della Pergola, more precisely in the kitchen-living room;
c. inside the building on Via della Pergola, in Meredith Kercher’s room;
d. inside the building of Raffaele Sollecito, in the kitchen-living room;
e. inside the building of Raffaele Sollecito, in the bedroom;
f. in the garden of the building on Via Sperandio 5 bis;
g. in Park S. Angelo, the place from which – beyond any doubt – Meredith Kercher’s cell phones were thrown;
h. all along the path between Via della Pergola and Via Sperandio 5 bis, capturing – about every 3 seconds - a new series of measurements and the GPS position of the instrument;
· averaged a great deal of the data acquired, in order to exclude any effect due to temporary irregularity (vehicle transit, etc.) and, finally, compared the results of the measurements according to the selection criteria of the cell set by the Technical Regulations in force, thus obtaining a clear and objective picture of each cell receivable in each site examined, with the evidence of which proved to be the best serving cell (that which would be chosen by the cell phone at the beginning of each communication).
In essence, the differences between the activities of the PM’s consultants and those of Dr. Pellero (consultant of Sollecito’s defence) appear very clear:
· the scientific police indicated an area of approximate coverage and carried out measurements devoid of the elements necessary to contextualize them with respect to the criterion applied by the mobile phones for the choice of the serving cell, limiting the surveys to instantaneous measurements in the vicinity of, but not coincident with, the places of investigative interest (for example, only outside of Meredith’s room and Raffaele’s building);
· Dr. Pellero displayed a detailed representation of the area of coverage, based on objective data acquired directly at the source from the cell phone operators; he made complete, exhaustive and repeatable measurements at the places of investigative interest (e.g. inside Meredith’s room and Raffaele’s building), extending the measurements also to other places of direct investigative interest
(for example, Parco Sant’Angelo, in the area from which Meredith’s cell phones were thrown into the garden of Lana’s house in Via Sperandio 5 bis).
Nonetheless, in the grounds for the judgment, only the results obtained by the scientific police were described as amongst the elements which contributed to the formation of the judgment, and there is no trace of the objective, complete and repeatable results obtained by Sollecito’s defence consultant.
It is a cold, gray and rainy beach here though. Still beautiful.