This page serves as a standalone directory for the scientific terms, historical figures, and criminal cases discussed in the podcast. It provides a scannable overview of the podcast’s scientific foundation. For a deep dive into the application of these terms, please refer to the corresponding episode titles in our archive. Last updated July 2026.
A
- ABO Blood Group System: The classification of human blood based on the inherited properties of red blood cells (A, B, AB, and O). The 1970s standard for biological screening. While it can exclude suspects, it is a “blunt instrument” that often only narrows a pool to 40% of the population (e.g., Type A), providing a shield of anonymity for predators like Rader before the DNA era. (Episode: Profile: Dennis Rader)
- Abrasion: A scrape or graze on the outermost layer of the skin caused by friction or blunt force. (Episode: Blunt Force Trauma)
- Accumulated Degree Days (ADD) / Hours (ADH): A mathematical calculation used in forensic entomology to measure thermal energy accumulated over time. Used to calculate the biological timeline of insect larvae development and establish the minimum Post-Mortem Interval. (Episode: The Science of the Body Farm)
- Acoustic Baffle / Masking: Spatial and structural engineering techniques used to deaden or drown out sound transmission. Audited in long-term confinement cases (e.g., Castro, Heidnik, Fritzl). (Episode: Abductions, Pt. 2)
- AFIS/IAFIS: (Integrated) Automated Fingerprint Identification System; the FBI’s national digital database for storing and matching fingerprints. (Episode: Fingerprints)
- Agglutination: The clumping of red blood cells when mixed with an incompatible antiserum; the basis of blood typing. (Episode: The History of DNA)
- Alvarez, Inspector: The investigator who used the first bloody fingerprint to solve a murder in 1892. (Episode: Fingerprints)
- Amygdalin: A cyanogenic glycoside found in the seeds of many fruits (apricots, peaches, apples). When digested, it releases hydrogen cyanide, acting as nature’s original “bitter” defense mechanism against ingestion. (Episode: Poisoning: Cyanide)
- Andrews, Tommie Lee: The first person in the U.S. to be convicted using DNA evidence (1987). (Episode: The History of DNA)
- Angle of Impact: The acute angle formed between the direction of a blood drop and the plane of the surface it strikes. As the angle becomes more acute, the stain becomes more elongated. (Episode: Blood Spatter)
- Area of Convergence: A two-dimensional view of the intersection of lines formed by the long axes of several individual bloodstains. This tells you where the victim was standing or sitting when the event occurred. (Episode: Blood Spatter)
- Area of Origin: The three-dimensional location from which blood spatter originated. This is determined by projecting the angles of impact back to a point in space (often using the “stringing” method). (Episode: Blood Spatter)
- Autolysis: The initial phase of biological decomposition where cellular membranes rupture, releasing digestive enzymes that break down surrounding tissues from the inside out. (Episode: The Science of the Body Farm)
B
- Backspatter: Blood directed back toward the source of the energy or force that caused the spatter (often found on the weapon or the hands of the shooter in close-range firearm cases). (Episode: Blood Spatter)
- Ballistic Topography (3D): The mechanical scanning of bullet jackets and casing surfaces to map micro-striations created by a firearm’s barrel, providing immutable toolmark identification. (Episode: Current Topics Science & Justice)
- Berry, Amanda: Cleveland abduction survivor whose rapid exploitation of an unlatched door breached Ariel Castro’s ten-year perimeter. (Episode: Abductions, Pt. 2)
- Biological Aerosols: Microscopic liquid or solid particles suspended in the air (e.g., shed squames, respiratory droplets) accelerated during physical struggle inside enclosed spaces. (Episode: Abductions, Pt. 1)
- Biological Defiance: The phenomenon where a victim defies expected biological timelines of fatal trauma or exsanguination, preserving active crime scene telemetry. (Episode: Abductions, Pt. 1)
- Bloodsworth, Kirk: The first death row inmate exonerated by DNA evidence in the U.S. (Episode: The History of DNA)
- Blunt Force Trauma: Physical trauma caused by a dull, non-penetrating external force impacting the body. (Episode: Blunt Force Trauma)
- Botha, Alison: 1994 South African survivor of catastrophic disembowelment and neck trauma whose biological defiance led directly to her attackers’ arrest. (Episode: Abductions, Pt. 1)
- BTK (Dennis Rader): Serial killer caught via metadata and familial DNA from a daughter’s pap smear. (Episode: DNA Profiling)
C
- Calliphoridae: The blowfly family; the primary biological indicator species used by forensic entomologists to establish time-of-colonization timelines. (Episode: The Science of the Body Farm)
- Cast-off Pattern: A bloodstain pattern created when blood is released or thrown from a moving blood-bearing object (like a hammer or a baseball bat) between blows. (Episode: Blood Spatter)
- Castro, Ariel: Isolationist captor who modified a standard Cleveland residential property into a boarded, compartmentalized vault. (Episode: Abductions, Pt. 2)
- Centimorgan (cM): The unit of genetic distance used to measure how much DNA two people share. If the count is high (e.g., 3,400 cM), the relationship is immediate; if it is low (e.g., 200 cM), the relationship is distant, such as a second cousin. (Episode: Spotlight: Colleen Fitzpatrick)
- Chain of Custody: The chronological paper trail of evidence. In toxicology cases like cyanide poisoning, this record is vital to prove that the blood samples were not tampered with or degraded between the autopsy and the lab. (Episode: Poisoning: Cyanide)
- Chimerism: A rare condition where an individual has two different sets of DNA, which can lead to false exclusions in forensic testing. (Episode: The History of DNA)
- CODIS: Combined DNA Index System; the generic term for the FBI’s program of support for criminal justice DNA databases. (Episode: The History of DNA)
- Cognitive Architecture of Interrogation: The psychological manipulation of risk equations and environmental stressors that forces compliance in interrogation rooms. (Episode: The Science of Confessions)
- Contusion: A bruise; damage to blood vessels causing bleeding under the skin without breaking the surface. (Episode: Blunt Force Trauma)
- Coup-Contrecoup: An internal injury where the brain strikes the site of impact (Coup) and then the opposite side of the skull (Contrecoup). (Episode: Blunt Force Trauma)
- Cowans, Stephan: First U.S. case where a fingerprint conviction was overturned by DNA. (Episode: Fingerprints)
- Cytochrome c Oxidase: The enzyme within the mitochondria that acts as the “cellular engine.” Cyanide binds to the iron within this enzyme, deadbolting the cell’s ability to use oxygen and causing systemic metabolic failure. (Episode: Poisoning: Cyanide)
- Czech, Amber: 2025 case involving fatal blunt force trauma via a sledgehammer. (Episode: Blunt Force Trauma)
D
- Dactyloscopy: The formal scientific study and analysis of fingerprint identification. (Episode: Fingerprints)
- Data Integrity: The operational requirement that analytical data remain uncorrupted, verifiable, and mathematically sound from initial collection through courtroom presentation. (Episode: Spotlight: The Innocence Project)
- Deangelo, Joseph James (Golden State Killer): Identified 44 years later through forensic genealogy. (Episode: DNA Profiling)
- Deceleration Trauma: Injury occurring when a rapidly moving body comes to an abrupt stop, causing internal organs to shift or tear. (Episode: Blunt Force Trauma)
- Defense Wounds: Injuries sustained (usually on hands or forearms) when a victim attempts to shield themselves from an attack. (Episode: Blunt Force Trauma)
- Directionality: The characteristic of a bloodstain that indicates the direction blood was moving at the time of impact. You can usually find this by looking at the “tail” of the drop. (Episode: Blood Spatter)
- Dobrowski, Jody: 2005 UK murder case involving severe blunt force and a homophobic motive. (Episode: Blunt Force Trauma)
E
F
- Familial DNA Search (Kinship Math): A tactical forensic pivot used when a suspect is not in the CODIS database. By analyzing the DNA of a close relative (such as a child’s clinical sample), investigators can identify a “familial half-signal” that leads directly to the biological father or mother. (Episode: Profile: Dennis Rader)
- Ferrous (Fe2+) vs. Ferric (Fe3+) Iron: The two valence states of iron in the body. Hemoglobin uses Ferrous iron to transport oxygen, while the mitochondria use Ferric iron to process it. Carbon Monoxide hijacks the former; Cyanide sabotages the latter. (Episode: Poisoning: Cyanide)
- FIGG (Forensic Investigative Genetic Genealogy): The field established by Colleen Fitzpatrick that combines high-resolution DNA analysis with traditional genealogical research to identify unidentified remains and suspects through their family trees. (Episode: Spotlight: Colleen Fitzpatrick)
- Fitzpatrick, Colleen: A pioneering American physicist and forensic genealogist who revolutionized the identification of “John and Jane Does” by applying the principles of signal-to-noise ratios from optical physics to degraded DNA samples. (Episode: Spotlight: Colleen Fitzpatrick)
- Forward Spatter: Blood that travels in the same direction as the source of energy or force (commonly associated with exit wounds in ballistic trauma). (Episode: Blood Spatter)
- Franklin Jr., Lonnie (Grim Sleeper): Serial killer identified via a partial DNA match from his son. (Episode: DNA Profiling)
- Friction Ridges: The raised lines on the skin of the fingers and palms that create unique identifiable patterns. (Episode: Fingerprints)
- Fritzl, Josef: Licensed electrical engineer who designed a subterranean, steel-reinforced concrete bunker beneath his Austrian home to hold his daughter captive for 24 years. (Episode: Abductions, Pt. 2)
G
- Galton, Francis: Author of Finger Prints (1892); established the individuality and permanence of prints. (Episode: Fingerprints)
- Gell, Alan: Exonerated death row inmate whose innocence was proven using blowfly larval instar growth clocks to dismantle a fraudulent prosecutorial timeline. (Episode: The Science of the Body Farm)
- Genetic Blind Spot (HCN): An X-linked trait that prevents 20% to 40% of the population from smelling the “bitter almond” scent of Hydrogen Cyanide, making it a significant professional hazard in the lab. (Episode: Poisoning: Cyanide)
- Grew, Nehemiah: First Western scientist to describe ridge patterns of fingers and palms (1684). (Episode: Fingerprints)
- GSR (Gunshot Residue): Microscopic traces of gunpowder and soot expelled when a firearm is discharged. (Episode: Trace Evidence)
H
- Heidnik, Gary: Disorganized captor who dug a primitive dirt pit in a Philadelphia basement, resulting in rapid environmental and biological system failure. (Episode: Abductions, Pt. 2)
- High-Velocity Spatter: A bloodstain pattern caused by a high-speed force (over 100 feet per second), such as a gunshot. It often looks like a fine mist of droplets less than 1mm in diameter. (Episode: Blood Spatter)
I
- Impression Evidence: Marks left when one object comes into contact with another, softer surface (e.g., tire tracks or shoe prints). (Episode: Trace Evidence)
J
K
L
- Laceration: A torn, ragged wound in the tissue caused by blunt force impact rather than a sharp blade. (Episode: Blunt Force Trauma)
- Landsteiner, Karl: Nobel Prize winner credited with discovering the ABO blood group system (1900). (Episode: The History of DNA)
- Latent Print: An “invisible” fingerprint left on a surface by natural oils and sweat, requiring powder or chemicals to visualize. (Episode: Fingerprints)
- Lee, Frances Glessner: Known as the “Mother of Forensic Science.” (Episode: Spotlight: Frances Lee)
- Lethal Injection Assay: The three-drug chemical protocol consisting of an anesthetic (Midazolam), a neuromuscular paralytic (Pancuronium Bromide), and an electrolyte bolus (Potassium Chloride) designed to induce cardiac arrest. (Episode: The Science of The Death Penalty)
- Linkage Disequilibrium: The forensic principle that DNA does not shuffle randomly but travels in inherited “blocks” called haplotypes. This allows genealogists to track ancestral traits across generations even in shattered or degraded samples. (Episode: Spotlight: Colleen Fitzpatrick)
- Locard’s Exchange Principle: The foundational principle that “every contact leaves a trace.” (Episode: Trace Evidence)
- Long, Bobby Joe: Serial killer caught via trilobal carpet fibers. (Episode: Trace Evidence)
M
- Medium-Velocity Spatter: Stains usually associated with blunt force trauma or stabbings, where the force is between 5 and 25 feet per second, resulting in drops 1mm to 4mm in size. (Episode: Blood Spatter)
- Metadata: Hidden “data about data” in digital files that can reveal authors, locations, and timestamps (e.g., the BTK floppy disk). (Episode: Profile: Dennis Rader)
- Micro-Environmental Prison: An engineered, static secondary location (cellar, boarded room, subterranean bunker) where the crime is not a transient event, but the physical environment itself. (Episode: Abductions, Pt. 2)
- Microarray Technology: A high-resolution forensic tool that uses a silicon chip packed with microscopic probes. Unlike traditional PCR, it can scan 600,000 to 800,000 locations on a DNA strand simultaneously to create a “4K satellite image” of an individual’s genome. (Episode: Spotlight: Colleen Fitzpatrick)
- Midazolam: A lipophilic sedative used as the initial drug in lethal injection protocols; audited for its distinct ceiling effect during high-adrenaline crisis spikes. (Episode: The Science of The Death Penalty)
- Miller, Bryan Patrick (Zombie Hunter): First investigation in North America cleared via genetic genealogy. (Episode: DNA Profiling)
- Minutiae: The tiny specific details within fingerprint ridges (dots, bifurcations, points) used to match prints manually. (Episode: Fingerprints)
- MMIW Data Integration Glitch: The database incompatibility between local, state, and federal law enforcement systems resulting in massive statistical erasure for Missing and Murdered Indigenous Women. (Episode: Current Topics Science & Justice)
N
- Neurodivergent Override: The specific vulnerability of non-standard neurotypes under interrogation pressure, where institutional authority alters risk-reward calculations toward compliance. (Episode: The Science of Confessions)
- Non-Newtonian Soil Mechanics: The physical behavior of compressed soil under footwear or tire tread pressure, releasing botanical VOCs and revealing mineral footprints. (Episode: Abductions, Pt. 1)
- Non-Secretor: An individual (approx. 20% of the population) whose blood type antigens are not found in their other body fluids. (Episode: The History of DNA)
- Norfolk Four: High-profile miscarriage of justice case highlighting the psychological mechanics of false confessions under interrogation pressure. (Episode: The Science of Confessions)
- Nutshell Studies of Unexplained Death: 1:20 scale dioramas used to train investigators in the art of observation and evidence collection. (Episode: Spotlight: Frances Lee)
O
P
- Pancuronium Bromide: A neuromuscular paralytic used in lethal injection protocols designed to freeze voluntary movement. (Episode: The Science of The Death Penalty)
- Partial Match: A DNA result that suggests a close relative of a suspect is in the database, rather than the suspect themselves. (Episode: DNA Profiling)
- Passive Drop (Gravity Drop): Bloodstain drops created solely by the force of gravity, usually circular if they hit a flat horizontal surface. (Episode: Blood Spatter)
- Patent Print: A visible fingerprint left in a foreign substance like blood, ink, or paint. (Episode: Fingerprints)
- PCR (Polymerase Chain Reaction): A technique used to “amplify” small or degraded DNA samples into millions of copies for testing. (Episode: The History of DNA)
- Pitchfork, Colin: The first murderer caught using DNA profiling. (Episode: The History of DNA)
- Plastic Print: A 3D fingerprint impression left in a soft material such as wax, soap, or wet paint. (Episode: Fingerprints)
- Post-Mortem Interval (PMI): The calculated time elapsed between biological death and the discovery of remains. (Episode: The Science of the Body Farm)
- Potassium Chloride: An electrolyte bolus used in lethal injection protocols to disrupt the cardiac sodium-potassium pump, inducing cardiac arrest. (Episode: The Science of The Death Penalty)
- Proteomics: The large-scale study of proteins; on the modern bench, synthetic DNA barcodes and peptide sequencing redefine trace evidence analysis from damaged samples. (Episode: Current Topics Science & Justice)
- Prussian Blue Reaction: A forensic test developed after the isolation of Prussic Acid. By adding ferrous sulfate to a sample, the invisible presence of cyanide is converted into a brilliant, deep blue pigment (Ferric Ferrocyanide), providing a visual “Aha!” moment in the lab. (Episode: Poisoning: Cyanide)
- Putrefaction: The secondary stage of decomposition driven by bacterial activity, resulting in gas production, tissue discoloration, and volatile chemical emissions (e.g., putrescine, cadaverine). (Episode: The Science of the Body Farm)
Q
R
- Ramirez, Richard (Night Stalker): Caught after a single fingerprint was recovered via laser detection. (Episode: Fingerprints)
- Rape Kit Backlog: The systemic administrative failure resulting in over 100,000 unanalyzed Sexual Assault Evidence Kits (SAEKs) sitting in law enforcement storage facilities nationwide. (Episode: Current Topics Science & Justice)
- RFLP (Restriction Fragment Length Polymorphism): An older, “cumbersome” DNA technology used in the late 80s and early 90s. It required large, pristine, “wet” biological samples, leading killers like Rader to falsely believe that small or old “dry” samples were biologically expired. (Episode: Profile: Dennis Rader)
- Rivera, Josefina: Abduction survivor who broke Gary Heidnik’s physical perimeter and alerted law enforcement from a payphone. (Episode: Abductions, Pt. 2)
- Roberson, Robert: High-profile Texas death row case involving contested shaken baby syndrome hypotheses and junk science claims. (Episode: Spotlight: The Innocence Project)
- Rojas, Francisca: First person convicted of murder using fingerprint evidence (1892). (Episode: Fingerprints)
S
- Shepard, Matthew: 1998 murder victim; his death became a catalyst for national hate crime legislation. (Episode: Blunt Force Trauma)
- Shy, Colonel William: Civil War exhumation case where an anaerobic iron coffin led to a 113-year PMI error, establishing the necessity for the University of Tennessee Anthropological Research Facility. (Episode: The Science of the Body Farm)
- Singleton, Lawrence: Perpetrator who abducted 15-year-old Mary Vincent, amputated her forearms, and left her in a remote canyon culvert. (Episode: Abductions, Pt. 1)
- SNP (Single Nucleotide Polymorphism): A single-letter change in the genetic code. While traditional forensics looks at 20 “stutters” (STRs), SNP mapping looks at hundreds of thousands of individual points to triangulate identity through distant relatives. (Episode: Spotlight: Colleen Fitzpatrick)
- Surface Tension: The “elastic” characteristic of the outer edge of a liquid that causes it to resist penetration. This is why blood travels through the air as a sphere, not a “teardrop” shape. (Episode: Blood Spatter)
- Systemic Failure Rate: The measurable percentage of error built into an operational or legal machine (e.g., the estimated 4.1% death row innocence baseline or the 7% lethal injection botch rate). (Episode: Spotlight: The Innocence Project)
T
- Taphonomy: The study of decaying organisms over time and how they interact with natural environmental processes, soil chemistry, and scavengers. (Episode: The Science of the Body Farm)
- Transient Execution Site: An unengineered, short-term secondary site (remote canyon, roadside clearing) used by an offender to clear a high-risk contact zone under the false assumption that nature will erase the biological evidence. (Episode: Abductions, Pt. 1)
- Trilobal Fibers: Synthetic carpet or clothing fibers with a distinct three-lobed shape, often used to link suspects to scenes. (Episode: Trace Evidence)
U
V
- Venous-Arterial PO2 Gradient: The measurement of the difference in oxygen pressure between the two sides of the circulatory loop. In cyanide cases, this gradient flattens because the cells cannot “eat” the oxygen, leaving the venous return as bright and oxygenated as the arterial supply. (Episode: Poisoning: Cyanide)
- Vincent, Mary: 1978 survivor of extreme trauma whose biological defiance and use of soil coagulation preserved crime scene telemetry leading to Lawrence Singleton’s capture. (Episode: Abductions, Pt. 1)
- Void Pattern: An absence of blood in an otherwise continuous bloodstain pattern. This suggests that an object (or person) was in the way during the event and has since been moved. (Episode: Blood Spatter)
- Volatile Organic Compounds (VOCs): Organic chemicals that easily evaporate into the air at ambient temperatures; used by cadaver dogs and GC-MS equipment to locate human decomposition plumes or plant stress markers. (Episode: The Science of the Body Farm)
- Vucetich, Juan: Pioneer who expanded fingerprint classification and applied friction ridge identification to criminal cases. (Episode: Fingerprints)
W
- Watson & Crick: Scientists who described the double-helix structure of DNA. (Episode: The History of DNA)
- Weapon Focus Effect: A survival-driven cognitive distortion where a victim’s visual attention is concentrated almost exclusively on a weapon, significantly corrupting memory encoding of the perpetrator’s facial features. (Episode: The Science of Eyewitness Testimony)
- Weapon of Opportunity: Any object found at a scene (not brought by the killer) that is used to commit an assault. (Episode: Blunt Force Trauma)
- Westerfield, David: Perpetrator who used a motorhome as a mobile containment unit in the 2002 murder of Danielle van Dam, creating a high-yield trace evidence trap. (Episode: Abductions, Pt. 1)
X
Y
- Y-STR (Y-chromosome Short Tandem Repeat): A specific genetic signature passed almost entirely intact from father to son. Because it travels with the patrilineal surname, it can be used to predict a suspect’s last name from a crime scene sample. (Episode: Spotlight: Colleen Fitzpatrick)