Some of the knives in the knife database of the NFI. Credit: NFI
After two years of research, forensic scientists at the Netherlands Forensic Institute have created a knife database they say is “concerning” and “shocking.”
Previous research and observational studies have shown that 12- to 18-year-olds are becoming increasingly involved in stabbing incidents. In the Netherlands, for example, the number of arrests of minors for illegal possession of firearms and stabbing weapons has increased sharply in recent years.
This caught the attention of scientists at the Netherlands Forensic Institute (NFI), as well as the local police.
After consultation with the police and the Public Prosecution Service, NFI was given permission to examine knives seized in the eastern Netherlands during searches or surrenders. The knives are normally destroyed, but have now been examined and catalogued in the creation of NFI’s new knife reference database.
Overall, the researchers report the use of “bigger and bigger knives” intended to cause as much injury as possible.
“The big knives are just swords,” says Peter Zoon, one of the creators of the database.
For example, the largest knives Zoon and co-creator Martin Janssen documented were more than half a meter long. For comparison’s sake, the average length of a knife blade examined by NFI in previous years was less than 15 cm. That’s a nearly 300% increase in the length of the blade over time.
To make matters worse, the knives are not only longer but more dangerous. In the last two years, about 900 knives were sold in the East Netherlands.
“These are, for example, knives with saw serrations, chopping knives and so-called Rambo knives. These are not knives you find in the kitchen drawer,” said Janssen.
The new database contains photos of the collected knives, as well as data on their composition. The NFI scientists said this information can help them estimate the type of knife used after a stabbing incident in which no weapon was recovered since the different coatings on knives leave different trace evidence.
“Ultimately, we want to be able to calculate the evidential value in criminal cases instead of estimating it with the information in the database. What is the probability that a certain type of knife was used compared to other knives?,” said Janssen.
The scientists say the database can also help quantitatively and qualitatively analyze data to identify meaningful patterns of a criminal organization. The more the database is built out, the easier it will be in the future for scientists and investigators to link certain types of knives or decorations to specific groups—a calling card of sorts.
“'If the NFI can put us on the trail of a certain type of knife, that will help in the investigation,” said policeman Guyon, who works with rival youth groups in The Hague, Netherlands. “Certain knives are common within youth groups. If we know that such a knife has been used, it may give us an indication of where to look. It can also be useful when searching a house if you know what kind of knife you are looking for.”
Guyon says the youths he encounters carry knives to defend themselves from others, but they also actively seek confrontation as “possession of stabbing weapons increases status.”