CSS Criminology Criminal Investigation and Forensics Syllabus

What are the main sources of information in an investigation?

People (victims, witnesses, informants, suspects), physical evidence, records and documents (public and private), and electronic/database sources.

Distinguish primary sources from secondary sources of information.

Primary sources provide firsthand, direct knowledge (eyewitnesses, original documents, physical evidence); secondary sources provide indirect, derived information (hearsay, reports about the event).

What is open-source intelligence (OSINT)?

Information gathered from publicly available sources such as media, internet, social media, public records, and academic publications, requiring no covert means.

What is the difference between an interview and an interrogation?

An interview is non-accusatory questioning of cooperative witnesses/victims to gather information; an interrogation is accusatory, structured questioning of a suspect to obtain admissions or a confession.

What is cognitive interviewing?

A witness interview technique that enhances memory recall by reinstating context, encouraging complete reporting, recalling events in varied order, and changing perspectives, without leading the witness.

What is a leading question and why avoid it in witness interviews?

A leading question suggests its own answer (e.g., 'The car was red, wasn't it?'); it should be avoided because it can contaminate memory and produce unreliable, suggested testimony.

What factors can affect the reliability of eyewitness testimony?

Lighting/visibility, distance, duration of observation, stress/weapon focus, time elapsed before recall, suggestive questioning, and the witness's own biases or perception limits.

What is rapport and why is it important in interviewing?

Rapport is a relationship of trust and cooperation between interviewer and subject; it encourages openness and fuller, more accurate disclosure of information.

What is the difference between an admission and a confession?

An admission is a statement acknowledging a fact that tends to incriminate but does not concede all elements of guilt; a confession is a full acknowledgment of guilt for the crime charged.

What are the Miranda warnings (rights of a suspect before custodial interrogation)?

The right to remain silent, that anything said may be used in court, the right to an attorney, and that an attorney will be provided if the suspect cannot afford one.

What is the Reid Technique of interrogation?

A nine-step accusatory interrogation method that moves a suspect from denial to confession through confrontation, theme development, handling denials/objections, and presenting alternative questions.

What is a false confession and what are its main types?

An admission of guilt for a crime not committed; types are voluntary (self-initiated), coerced-compliant (to escape pressure), and coerced-internalized (the suspect comes to believe they are guilty).

What is modus operandi (MO)?

An offender's characteristic, learned method of committing a crime (entry, tools, targets, techniques), which can change over time and is used to link crimes to the same perpetrator.

How does a criminal's 'signature' differ from modus operandi?

MO is the functional method needed to complete the crime and can evolve; signature is the unnecessary, ritualistic behavior fulfilling psychological needs and tends to remain consistent.

What is criminal profiling?

An investigative technique that infers an offender's likely characteristics (personality, behavior, demographics) from crime scene evidence and victimology to narrow the suspect pool.

What is crime mapping / hotspot analysis?

The use of GIS and spatial data to plot and analyze where crimes cluster (hotspots), helping allocate resources and predict where future crimes are likely.

What is link analysis in criminal analysis?

A technique that visualizes and examines relationships among people, places, events, and transactions to uncover networks, especially in organized and financial crime.

What is forensic science?

The application of scientific principles and methods to the analysis of physical evidence for use in legal proceedings and the investigation of crime.

What is the difference between class characteristics and individual characteristics of evidence?

Class characteristics place evidence in a group/category (e.g., blood type, shoe size); individual characteristics can be traced to a single source (e.g., fingerprint, tool mark, DNA).

What is the chain of custody?

The documented, unbroken record of every person who handled an item of evidence, with times and conditions of transfer, used to prove the evidence is authentic and untampered for court.

What is trace evidence? Give examples.

Small, often microscopic material transferred during a crime — examples include hair, fibers, glass fragments, paint chips, soil, and gunshot residue.

Distinguish direct evidence from circumstantial evidence.

Direct evidence proves a fact without inference (e.g., eyewitness seeing the act); circumstantial evidence requires inference to connect it to a conclusion (e.g., fingerprints at the scene).

What is the structure of DNA used for forensic identification?

DNA is a double helix of two strands held by complementary base pairs — Adenine-Thymine and Guanine-Cytosine — with sequence variations (especially STRs) providing unique individual identity.

What are STRs in DNA analysis?

Short Tandem Repeats — short DNA sequences repeated a variable number of times that differ among individuals; comparing repeat counts at multiple loci yields a highly discriminating DNA profile.

Why is mitochondrial DNA (mtDNA) useful in forensics?

mtDNA is maternally inherited and present in many copies per cell, so it can be recovered from degraded samples, hair shafts, and bones where nuclear DNA is unavailable, though it is shared among maternal relatives.

What are the three basic fingerprint pattern types?

Loops, Whorls, and Arches (with loops being the most common, roughly 60-65% of patterns).

What are the three types of fingerprints found at crime scenes?

Latent (invisible, from sweat/oils, needing development), patent (visible impressions in blood, ink, dust), and plastic (three-dimensional impressions in soft material like wax or putty).

What are minutiae in fingerprint analysis?

The specific ridge characteristics — ridge endings, bifurcations, dots, and islands — whose type and relative position are compared to individualize and match fingerprints.

What is digital/cyber forensics?

The branch of forensic science dealing with the identification, preservation, extraction, analysis, and documentation of electronic evidence from computers, mobile devices, and networks for legal use.

What is a forensic hash value (e.g., MD5/SHA) and why is it used in digital forensics?

A hash is a fixed-length digital fingerprint computed from data; matching hash values before and after acquisition prove the evidence (forensic image) was not altered, ensuring integrity.

What are the key steps in crime scene management?

Secure and isolate the scene, conduct a preliminary survey, document (photograph, sketch, notes), search systematically, collect and package evidence, maintain chain of custody, and conduct a final survey/release.