Can Blood Evidence Still Be Found After a Crime Scene Is Cleaned?
Cleaning a crime scene does not always remove the evidence.
A Flinders University study looked at how different cleaning methods affect blood-derived DNA and haemoglobin on cotton fabric and metal knife blades. The research found that the survival of biological evidence depends on several factors, including the surface type, whether the blood was wet or dry, and which cleaning method was used.
This matters because offenders may attempt to clean a scene before investigators arrive. But even when stains are no longer visible, traces may still remain.
The study found that some methods were more effective than others. Bleach and hot running water removed more haemoglobin from cotton and knife blades, while other combinations affected DNA removal differently.
For investigators, the key point is that cleaning does not automatically mean evidence is gone.
Blood evidence can behave differently depending on the material it touches. Fabric may retain traces in fibres, while metal surfaces may respond differently to cleaning agents. That is why proper forensic testing is so important.
This research reinforces a simple but important idea. A scene that looks clean may still hold useful information.
Forensic teams need to understand not only what evidence is present, but how it may have changed after an attempt to remove it.
Reference source: https://news.flinders.edu.au/blog/2026/03/03/crime-scene-investigations-put-to-the-test/