It’s all about a murder of a Frisian accountant. The suspects in this case had staged the victim’s suicide and even written a farewell email. The police did not trust the case and called in the NFI to investigate whether the farewell email had really been written by the victim or whether someone else was responsible for it – and whether it was therefore a murder instead of a suicide. This is called author recognition.
“Author recognition is about having a piece of text that was written by someone – by a perpetrator of a crime – and then you see whether it was the suspect who wrote the piece or whether it was someone else,” says Wauter Bosma, forensic data analyst at the NFI. This could be an email or, for example, a series of apps.
Three possible authors
In this case there were three possible authors, two suspects and a victim. “We looked at material from all three people that says something about how those three authors write, and we compared that with the suicide note.” An email in this case. “And we have concluded that the writing style in this case fits one of the suspects better than the other two candidates.”
In practice, all traces are first examined, for example on which computer was the letter written? “But if that leads to nothing and the content is all that remains, then we can look at it.”
Everyday things
“For example, we look at safe words that someone uses,” Bosma continues. “But also to everyday things that everyone uses: articles, prepositions or personal pronouns. These appear to be identifying: the same words are used, but not in the same way. And because the writing style is used unconsciously, it is difficult to imitate it.”
The suspect in this murder case has been sentenced to 16 years in prison.
