Prints Revealed by Luminol Without Useful Biological Profile
[Impronte evidenziate dal luminol senza profilo biologico utile, pp. 106 – 110; translated by roteoctober]
Findings consisting of latent footprints detected with luminol in Knox’s room and in the corridor of the house on Via Della Pergola, which turned out to be devoid of any useful biological profile, have been marked with numbers 1,2 and 7.
Evaluation of these was also entrusted by the Public Minister to Dr. Rinaldi and Inspector Boemia.
The latter two have explained (ruling, from p. 369) that the corresponding photographs were characterized by the absence of metric reference. They [the photos] had also not been taken perpendicularly to the floor, where [the footprints] had been left, so that an operation of perspective-correction had been needed.
This was performed by comparison to Exhibit 5, which had a reliable metric reference. This allowed them to obtain the dimensions of the floor tile where the footprints had been left. The first measurement obtained was 169.3 mm for height and 336 mm for base. A subsequent revision [ripensamento] reduced the height to 162 mm.
According to the consultants of the Public Minister (ruling, from p. 371), Exhibit 1, collected in Knox’s bedroom, is a right footprint compatible with the one of reference, obtained from Knox.
Exhibit 2, collected in the corridor directed outward, is a right footprint, compatible with the one of reference, obtained from Sollecito.
Exhibit 7, collected in the corridor, in front of Meredith Kercher’s bedroom’s door and oriented towards the bedroom, is a right footprint compatible with the one of reference, obtained from Knox.
This Court finds that this evidence is totally irrelevant for the purpose of attributing responsibility to the defendants.
First of all, as Rinaldi and Boemia themselves say, these exhibits are useful only for negative comparisons and not for positive ones, since they lack the details present on the papillary crests.
Moreover, they maintain that the footprints were made from only the likely deposition of blood. They reach this conclusion simply because the detection occurred via reaction with luminol.
It has been stated above, however, that many other substances, some in common use, react with luminol, so that attributing even merely the likelihood of the presence of blood seems inadequate in the extreme: more appropriate would have been the assertion of simple possibility.
On the other hand, the exclusion of presence of blood, according to the tetramethylbenzidine test, in the footprints considered previously, leads one to conclude that it is most improbable that blood is present instead in these [here], and in these only.
Such a conclusion can be reached, at least for the footprint in Exhibit 7, also from merely logical considerations. It has been said that it is a right footprint oriented towards Meredith’s room: it is reasonable to think that, had it been left by bloodstains it would have been oriented outward [from Meredith’s room]. Rebus sic stantibus [Latin: “things being this way”], on the contrary, a plausible explanation should be given for its opposite orientation; nothing of the kind is found in the ruling.
The presence of the prints attributed to Amanda is, however, fully justified by the fact that she lived in the house, and certainly it happened sometimes that she walked around barefoot, leaving traces on the floor, which had become responsive [to luminol] because of the use of some cleaning product or some other substance sensitive to luminol.
Similar justification can be found for the only print attributed to Raffaele Sollecito (Exhibit no. 2). According to Amanda, he went perhaps three times to [the house on] Via Della Pergola (ruling p. 65) when Meredith was present, and (ruling, pp. 54 and 55) on November 1st he and Amanda stayed at the cottage alone, after eating lunch. As they were a newly formed young couple, together for only a few days, it is not unlikely that in that situation they were intimate with each other [si siano intrattenuti in intimità] , even taking a few steps barefoot.
In any case, there are doubts also concerning the accuracy of the compatibility evaluation claimed by the consultant for the Public Minister on the basis of dimensional estimates.
Professor Vinci, consultant for Sollecito, has highlighted (from p. 69) all the morphological differences between the footprint present on Exhibit 2 and the comparison print, taken from Sollecito.
As seen in another section, Raffaele Sollecito’s footprint shows notable specific characteristics: missing impression [appoggio] of the distal phalanx of the second toe, and missing impression of the first phalanx of the big toe.
On the contrary, visually examining the two prints under scrutiny [Sollecito’s reference and Exhibit 2], both the print of the second toe and the impression of the first phalanx of the big toe are evident in Exhibit 2.
This same visual inspection also reveals further differences, concerning the different placement of the superior extremity of the frontal part of the heel and the differing rightward curve.
Professor Vinci also listed other – less evident – differences: the shape of the line obtained by connecting the apex of the toes and the position of all the toes, with specific reference to the trace of the fifth toe.
Concering the metric analysis, Sollecito’s consultant has stated beforehand that the photographic documentation of the footprints detected by luminol during the inspection of December 18th 2007 suffers from serious technical flaws, since it was not taken orthogonally to the detected footprints and since fluorescent ribbons were not used as precise metric references.
This fact [not using the ribbons] prompted Dr.Rinaldi and Inspector Boemia to perform the perspective-correction which was briefly mentioned above.
A first result was however admitted to be faulty at the hearing of May 9th 2009 by Rinaldi himself, who attributed it to a parallax error and claimed to have corrected it by bringing back right angles to 90 degrees and recalculating the measurements, without, however, describing the criterion and the calculations applied.
These reference parameters, so laboriously derived, produced measurements of the footprint revealed by luminol with values completely different between the Rinaldi – Boemia report and that of Vinci. According to the latter, the foot that left [the print] is considerably smaller than that of Sollecito, a measure consistent with a 36-37 size.
Now, in the face of these objections, all of them dutifully and convincingly documented, concerning both the morphological and the dimensional characteristics of Exhibit 2, absolutely nothing is said in the ruling about the reasons which prompted the first-level Court to prefer the results of Rinaldi – Boemia. These results have been accepted, one could say, “without looking”, without even mentioning Vinci’s contrary arguments.
All these considerations aside, however, it must be reiterated that the footprint in Exhibit 2 has no value [efficacia] from the prosecution point of view, considering that Rinaldi and Boemia themselves described it as useful only for negative comparisons and not for positive ones.
The absence of a biological profile must furthermore lead one to rule out that they were [recte: it was] impressed with blood; and finally, the frequentation of the house by Sollecito justifies their [its] presence, as noted before.
Entirely analogous arguments apply to Exhibits 1 and 7, attributed to Amanda Knox.
At the hearing of July 6, 2009, Professor Torre, consultant for Knox, showed that, in terms of morphology, Knox’s right foot has the second toe longer that the big toe, the opposite of [what was seen in] the footprints detected by luminol. Regardless of this, even to this Court it seems clear, from a comparison of the images of the Rinaldi – Boemia Report itself, that the position of all the toes is different.
No mention of this either is in the ruling.
In any case, it must be said that the presence of Knox’s footprints, above all the one of Exhibit 1, detected in her room, is even less relevant, since she lived in that house and could have left them at any time.
Naturally, the statement that they are useful only for negative comparisons, and the lack of a demonstration that they were impressed with blood, apply to these [prints] as well.