Familial Searching
Definition
The deliberate use of partial DNA profile matches in a forensic database to identify biological relatives of an unknown contributor, on the theory that a partial match indicates a close relative. Legal in the UK and some US states; prohibited in Germany; subject to varying restrictions internationally.
- Search method
- Partial STR (short tandem repeat) matches in forensic databases
- Legal status
- Permitted in UK and some US states; prohibited in Germany; varies by jurisdiction
- Scope
- Identifies biological relatives of unknown DNA contributor, not just direct suspects
Common questions
What does familial searching actually do?+
It looks for partial DNA profile matches in forensic databases. If a suspect's full DNA doesn't match the crime scene profile, but a partial match appears, that suggests the unknown contributor might be a biological relative of someone in the database. Investigators then follow up on those relatives as potential leads.
Is familial searching legal everywhere?+
No. It's legal in the UK and some US states, but prohibited in Germany and other jurisdictions. Legal status varies widely internationally, so investigators must check local rules before using it.
What's the main concern people raise about it?+
It investigates people who are not themselves suspects. Just because you're a relative of someone in a DNA database doesn't mean you committed the crime. This raises both civil liberties and effectiveness questions.
Related terms
- Bharatiya Sakshya Adhiniyam 2023 (BSA)
- India's current evidence statute, which replaced the Indian Evidence Act 1872. Section 63 of the BSA governs electronic records and requires a...
- BSA 2023 § 39
- Section 39 of the Bharatiya Sakshya Adhiniyam 2023, the provision governing expert opinion evidence in Indian courts. Replaced Indian Evidence Act 1872...
- CODIS
- The FBI's Combined DNA Index System, the US national STR-based forensic DNA database. Contains profiles from convicted offenders, arrestees, and unidentified crime-scene...
- Cold Hit
- A database match between a crime-scene DNA profile and an offender or arrestee profile where no other investigative lead identified the suspect....
- Daubert Standard
- The US federal evidentiary standard (Daubert v. Merrell Dow Pharmaceuticals, 1993) requiring that expert testimony be based on scientifically valid methods with...
- ELSI (Ethical, Legal and Social Implications)
- The research domain and policy framework addressing the broader consequences of genetic science, including forensic genetics: familial searching, genetic privacy, consent, discriminatory...
- Forensic Database
- A searchable repository of DNA profiles, fingerprints, images, or other forensic data from known individuals, crime scenes, or both. Includes national DNA...
- Frye Standard
- The US legal test for admissibility of scientific evidence, originating from Frye v. United States (1923), which required that a technique be...
- Machine Learning (Forensic Application)
- Statistical models trained on labelled forensic datasets to score or classify pattern evidence, such as fingerprints, toolmarks, or faces. Produces quantified similarity...
- People V. Castro (1989)
- New York Supreme Court case in which early RFLP DNA evidence was excluded under the Frye standard because the specific testing procedures...
- Portable/field Instrument
- A handheld or transportable analytical device, such as a Raman spectrometer, XRF analyser, or rapid-DNA cartridge system, designed for use outside a...
- Probabilistic Genotyping
- Software-based interpretation of complex DNA electropherograms using continuous statistical models (e.g. STRmix, TrueAllele, ArmedXpert). Generates a likelihood ratio for complex mixtures previously...
Explained in these topics
- Admissibility and Ethics: Daubert, Frye, R v. Doheny and ELSIThe deliberate use of partial DNA profile matches in a forensic database to identify biological relatives of an unknown contributor, on the theory that a parti...
- DNA Evidence: Legislation, Databases and PrivacyA deliberate search of a forensic database for partial profile matches, aimed at identifying biological relatives of an unknown contributor who are already in...
- The Future of Forensic Science: AI, Databases, Rapid MethodsA database search strategy that looks for partial STR matches as an indicator that a relative of the unknown contributor may be in the database. Legal status v...