Forensic study of authenticity of e-mails

Nowadays, technology is very present in our lives, so that more and more, computer-based evidence is part of everyday life in the judicial field. One of the most common cases is the accreditation or challenge of facts through e-mails, in which it is sought to determine the origin, authenticity and integrity of the same.

It is very common, to commit the temerity, to present an e-mail printed on paper as evidence in a judicial proceeding. In this case, the evidence is rebuttable since e-mails, given their nature, may be manipulated, and their mere printed presentation is not enough to prove their origin, authenticity and integrity.

As it is indicated in the Supreme Court Judgment 300/2015, May 19th , 2015 the proof of facts by means of e-mail “… is approached with all caution by the courts of justice. The challenge of the same displaces the burden of proof on those who intend to take advantage of their probative suitability. In such a case, the practice of an expert evidence will be essential … “.

Some interesting judgements

“As has been stated, the reason is based on the lack of legalize of the screenshots of the e-mails and WhatsApp on which the incriminating claim of the complainant is based. These screenshots have not, in fact, been duly noted. Neither has any expert evidence been requested on the matter.

“… therefore, although in the present case the documents have been challenged … and the defendant has not proposed expert evidence to prove the authenticity of these e-mails, according to the doctrine set forth, this does not exclude that the court judge can assess such documents in accordance with the rules of sound criticism, being able to give them relevance provided that there are other elements of judgment in the process that can be assessed with it, thus combining their content.”


This type of evidence can be contested and therefore, rejected, ruining the entire procedure. To determine whether this type of evidence can display probative value, the forensic analysis of a certified computer expert is essential.
Likewise, we must bear in mind that in recent years, the number of works and computer expert opinions that are dismissed in litigation and are not taken into account at the time of sentencing. The reason is none other than a huge increase in the number of computer experts who are not legally authorized to act before the courts, and who therefore incur in the crime of professional intrusion. We can find a clear example in the Judgment of the Superior Court of Justice of Madrid 531/2017, Social Chamber, Section 4, July 19th , 2017, in which it is stated in the first point of the grounds of law, that:

“The appealed ruling is essentially based on the ineffective and invalid expert evidence that has been provided as the only justification for the facts imputed in the letter of dismissal to the plaintiff, for several reasons explained by the Magistrate of Instance in her ruling. The first is because she understands that the expert presented by the company lacks an official degree in computer science, although at this point it is recognized that the expert is the person who provides computer assistance to the company as a freelancer, which implies at least a practical knowledge of what he is hired for. On the other hand, the informal nature of the expert evidence and the questioning of the chain of custody are argued. Special mention is also made of the breach of the guarantees of the plaintiff’s right to privacy at the time of carrying out the inspection and search of the computer equipment, declaring it proven that the plaintiff was not present. In short, the Magistrate of Instance, evaluating this evidence and the testimonies provided at the oral trial concludes that the defects in the practice of the expert evidence carried out by the company prevent granting probative value to this means of proof, and given that it is essential to prove the facts imputed to the plaintiff, declares the dismissal unjustified.”

The computer test must be certified in a computer expert opinion, prepared by a legally qualified computer expert. In our Frequently Asked Questions section you can find more information about it.

Why hire our services?

From FORENSICTECH we provide our clients with the security of having:

  • A computer expert specialized in your case, collegiate and legally authorized to act in the Spanish courts of justice.
  • Appropriate instruments and specialized software to develop your expert report.
  • Legally recognized chain of custody investigation and assurance methods.
  • An effective and efficient work in the requested expert report.
  • A certified computer expert opinion, which greatly increases your credibility and reliability before judicial bodies, as it is endorsed by a professional association.
  • A computer expert capable of facing the ratification in oral proceedings in all jurisdictional orders.
  • Our performance in all the courts of justice throughout Spain in all jurisdictional areas.


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