Under what circumstances is it necessary to detect traces of blood or amplify their signal?

In cases of wilful or natural alteration of bloodstains or the deposition of bloodstains on dark surfaces (clothing, objects, a burnt scene, etc.), it is sometimes necessary to be able to detect bloodstains invisible to the naked eye or to improve their visibility.

The use of specific chemical reagents and dedicated materials for the detection of latent or low-contrast blood traces allows the morpho-analyst to:

To highlight traces of blood invisible to the naked eye due to their natural or deliberate degradation (weathering, cleaning…)
To improve the contrast of faint bloodstains to enable interpretation of the events that caused them
To take samples to allow for subsequent genetic analysis

Implemented during crime scene or laboratory expertise operations, complementing or independently of a bloodstain morpho-analysis, these different detection and analysis methods are essentially based on the forensic strategy determined during the initial assessment of the mission assigned to the expert (identification of the problem encountered, technical and scientific police operations already carried out or to come, conditions for preserving the premises or exhibits to be examined...).

Methodology and contribution to investigations

Chemical detection

Detecting traces of blood invisible to the naked eye for genetic analysis (mandatory) and evidencing the cleaning actions

Signal boosting

Improve the contrast of faint blood traces to identify their source (type of object, fingerprints or shoe prints...)

Infrared or ultraviolet radiation examination

Optimising the detection of blood traces on low-reflectance surfaces (dark clothing, etc.) to maximise their informational power (mechanical identification and morpho-analysis interpretation).

Missions and results

Evaluation of forensic strategy and the relevance of latent bloodstain detection operations
Scene examination or laboratory forensics
Carrying out genetic sampling
Drafting the expert report (integration of genetic analysis results, evaluation of hypotheses...)
Provision of virtual tours (crime scene, seals, etc.)
Lodging of pleadings before the trial courts

BIOLEX forensic laboratory

When requesting expertise from Laboratoire BIOLEX, the justice system ensures the collaboration of a partner recognised for:

Its specialised expertise

Over 20 years' experience
in BPA and forensic science

its state-of-the-art equipment

State-of-the-art crime scene detection, 3D modelling, and virtualisation materials and software

its validated methods

Analyses carried out in accordance with current international protocols

Our team

Dr Christophe Petit

DirectEUr

Dr. Véronique Petit

Co-founder

Franck Le Roux

Bloodstain Pattern Analyst

Contact us

We remain at your disposal should you require any further information or expertise.

Detection and enhancement latent traces of blood or low contrast