Murray-Tedrow Framework
Definition
The tiered forensic-soil comparison protocol established by Raymond Murray and John Tedrow in their 1992 text 'Forensic Geology,' which organises soil examination techniques from cheap first-tier screening to expensive fourth-tier biological analysis.
- Primary source
- Forensic Geology (1992) by Raymond Murray and John Tedrow
- Methodology type
- Tiered soil comparison protocol
- Geographic scope
- US and international forensic soil science
Common questions
What is the Murray-Tedrow framework used for?+
It is a tiered protocol for comparing soil samples in forensic geology. The framework organizes soil examination from cheap initial screening tests all the way through expensive biological analysis, helping investigators match soil evidence to suspect locations or sources.
Why is the Murray-Tedrow framework considered the main reference in forensic soil science?+
It was developed by Raymond Murray and John Tedrow and documented in their 1992 book Forensic Geology. This tiered approach became the primary methodological reference used in the US and internationally for forensic soil comparison casework.
How does the tiered approach help in soil analysis?+
The framework allows investigators to start with simple, low-cost first-tier screening techniques to rule out obvious mismatches, then escalate to more expensive higher-tier tests, up to and including biological analysis, only when needed. This makes soil evidence work practical and cost-effective.
Related terms
- Bayesian Inference
- A framework for updating probability estimates in the light of new evidence; in forensic science, used to combine the prior probability of...
- Bromobenzene
- C6H5Br, density 1.50 g/cm3; the lighter component of the forensic density-gradient liquid mixture.
- Bromoform
- CHBr3, density 2.89 g/cm3; the denser component of the forensic density-gradient liquid mixture, used to create the bottom of the density range.
- Control Sample
- A water sample collected from the suspected drowning environment at or shortly after the time of body recovery. Its diatom assemblage is...
- D-Spacing
- The perpendicular distance between adjacent parallel planes of atoms in a crystal lattice, measured in angstroms or nanometres. Each set of planes...
- Density-Gradient Column
- Glass column filled with stepwise layers of liquids of decreasing density (commonly bromoform 2.89 g/cm3 and bromobenzene 1.50 g/cm3 mixed in known...
- Diatom Frustule
- The siliceous cell wall of a diatom, composed of biogenic opal; species-specific in shape and ornament, and resistant to degradation in soil...
- ENFSI ENG-FG1
- The European Network of Forensic Science Institutes' guidelines for forensic geological evidence, published in 2018 by the Expert Working Group on Forensic...
- FBI Soil Examination Unit
- The specialist unit at the FBI Laboratory in Quantico, Virginia, that has conducted forensic soil comparisons in federal criminal cases since the...
- Forensic Palynology
- The application of pollen and spore analysis to legal investigations. A forensic palynologist identifies the species composition of pollen assemblages from crime-scene...
- Heavy-Mineral Fraction
- The sub-fraction of soil mineral grains with density above 2.85 g/cm3, including pyroxene, hornblende, garnet, zircon, rutile, and tourmaline; particularly diagnostic of...
- Indicator Species (Pollen)
- Pollen taxa with restricted geographic ranges or specific habitat requirements, contrasted with background species that occur everywhere; indicator species provide site-specific geographic...
Explained in these topics
- Soil Comparison Casework and Statistical InferenceThe tiered forensic-soil comparison protocol developed by Raymond Murray and John Tedrow, documented in their 1992 and 2017 books on forensic geology; the prim...
- Soil Examination: Density Gradient, Mineralogy and PalynologyThe tiered forensic-soil comparison protocol established by Raymond Murray and John Tedrow in their 1992 text 'Forensic Geology,' which organises soil examinat...