Added value of palm prints for investigating crimes

The police and public prosecution service want to take palm prints of every suspect to increase the efficacy of investigations. They consider the distinction in the law between finger marks and palm marks to be arbitrary, as in both cases it concerns friction-ridge evidence. Repeated calls have also been made in the Dutch Parliament for palm prints to be routinely taken. On behalf of the WODC (Research and Documentation Centre), NSCR and VU Amsterdam investigated the legal aspects of palm marks and prints and how these are used in practice.

Palm mark provides information about a perpetrator’s actions

As palm marks cover a greater surface area than finger marks, they provide more information and can also give clear indications about the perpetrator’s actions. If a knife was used to stab someone dead, then the palm mark produced is different than if the same knife was used to cut something. So palm marks show what the perpetrator did with the knife. Sometimes a palm mark is the only evidence clear enough to point to a suspect. DNA can easily be transferred from one location to another, such as a cigarette butt dropped at the crime scene by somebody else. A palm mark is far more likely to originate from the perpetrator than a DNA sample.

Number of palm prints taken has decreased due to legal constraints

Friction-ridge evidence, such as finger marks and palm marks, are among the oldest and most effective means of identification. Friction-ridge evidence at a crime scene can be compared with prints taken earlier from a suspect and entered in HAVANK, the Dutch database for friction-ridge evidence. HAVANK automatically searches for similarities between marks and prints. Due to legal constraints, however, the number of palm prints in HAVANK has decreased since 2011, and so the chance of a match between mark and print has become smaller. This is hampering investigations.­

Advice: use palm prints on a broader scale

For the NSCR and VU Amsterdam research project, interviews were held with employees involved in the investigation and prosecution process and from the Netherlands Forensic Institute, court rulings were analysed and dossiers were investigated. Based on the outcomes, the researchers conclude that it should be possible to use palm marks and prints on a broader scale due to their added value. They do, however, sound a note of caution: friction-ridge evidence is not hard evidence. The marks at the crime scene can be vague or distorted. Experts sometimes have a different assessment on whether a mark matches a print. The researchers therefore recommend giving greater consideration to the multi-interpretability and subjective nature of friction-ridge evidence. Experts must report uncertainties more clearly, and judges should be cautious in how they deal with these friction-ridge evidence reports.

Using palm marks in practice

Palm marks give information about various types of crimes: burglaries, violent theft, robberies and ram-raids, manslaughter, murder, grievous bodily harm, dealing in cocaine and hemp nurseries. Most palm marks are found in common crimes such as burglaries. With burglaries, it often concerns marks made on the window frame when climbing in. Palm marks are often found in hemp nurseries, for example on tools or lamps because these are harder to handle with gloves on. With serious crimes, such as grievous bodily harm, manslaughter and murder, palm marks are found quite frequently.

Publication details and further reading

Malsch, M., Berg, T., Van den Hornman, M., Lammers, M., De Wilde, B. & Stevens, L. (2017). De toepassing van handpalmafdrukken voor de opsporing en vervolging (The use of palm marks for the investigation and prosecution process). The research was carried out on behalf of WODC (Research and Documentation Centre).
Alternatively, read the summarising article (Dutch only).