Types of Evidence in Criminal Justice

Evidence Types

• Motive refers to the reason behind committing a crime.
• Opportunity is the timeframe when the crime could have been committed.
• Locard's Exchange Principle states that whenever two objects come into contact, there's an exchange of material.
• Class Evidence cannot identify an individual, such as blood type.
• Individual Evidence can be linked to a specific person, such as fingerprints.
• Conditional Evidence is produced by a specific event or action, like blood, hair, or fibers.
• Transfer Evidence involves the transfer of physical material between objects or people.
• Transient Evidence degrades or disappears over time, like fingerprints, tire tracks, or smells.
• Pattern Evidence results from specific patterns left by contact, such as impressions or imprints.
• Direct Evidence is factual information based on witness testimony, like personal accounts.
• Indirect Evidence does not directly prove guilt but can lead to inferences about guilt.

Blood Tests

• The Kastle-Meyer Test uses a chemical indicator that turns pink when positive for blood.
• The test can show false positives with substances like horseradish, potato, and saliva.
• It does not distinguish between human and animal blood.
• Luminol reacts with blood, producing a pale blue color.
• The Luminol test can also produce false positives, including with bleach and iron. It does not distinguish between animal and human blood.
• Hemastix can detect blood with a green color change when positive.
• False positive results for Hemastix can occur with items like tomato, potatoes, rust, and bleach.

Fingerprint Analysis

• Fingerprints are individual evidence, meaning no two people have the same fingerprints.
• Ridge details (endings, bifurcations, and dots) are used to identify individual fingerprints.
• Fingerprint types include loops, whorls, and arches.
• Galton details are specific ridge characteristics used to identify fingerprints.
• Fingerprints can be both individual and class evidence, using ridge details and patterns to identify individual differences.

DNA Matching

• DNA sequencing involves comparing an individual's DNA to a database.
• Gel electrophoresis separates DNA fragments based on size.
• Nuclear DNA is present in blood cells (white, but not red) and hair roots.
• Human hairs are generally consistent in color and pigmentation, but animal hairs can exhibit color changes over short distances.

Password Security

• Passwords should be at least 12 characters long and include a mixture of upper and lowercase letters, numbers, and special characters.

Types of Attacks

• Phishing involves sending scam emails or text messages with links to malicious websites.
• Spearphishing targets specific individuals, groups, or organizations.
• Whaling is a type of phishing that targets high-profile individuals.
• White hat hackers are ethical security researchers who help organizations improve cybersecurity.
• Black hat hackers are criminals who intentionally enter computer networks with malicious intent.
• Grey hat hackers are computer security experts who sometimes operate outside of ethical standards, but usually not with malicious intent.
• Brute force attacks involve using trial and error to crack passwords.

Latent Print Methods

• Dusting uses a dark powder to visualize latent fingerprints.
• Iodine vapor is used to visualize latent fingerprints on porous surfaces.
• Superglue method is used to visualize latent fingerprints on non-porous surfaces.

Forensic Entomology

• Metamorphosis in insects involves distinct stages (egg, larva, pupa, adult).
• Accumulated Degree-Hours quantify the thermal energy required for insect development stages.
• Forensic Entomology is the study of insects in relation to criminal cases.

Hair Structure

• The hair shaft consists of a cortex (pigment portion), medulla (central portion), and cuticle (outermost layer).

Insect Succession

• Instar is a phase between two molting periods in insects.
• Larva is the immature form of an insect.
• Maggot is a soft-bodied, legless larva typically found in decaying matter.
• Pupa is the stage between larva and adult.
• Oviposition is the process of laying eggs.
• Spiracles are insect respiratory organs.

Stages of Decay

• Fresh Decay (Days 1-3): Initial decay, no significant signs.
• Putrefaction (Days 4-10): Odor, discoloration, bloating.
• Black Putrefaction (Days 10-120): Body darkens, gases released.
• Butyric Fermentation (Days 20-50): Foul odor, cheese-like appearance.
• Dry Decay (Days 50-365): Body dries, bones remaining.

Relationship of Blowflies to Decay

• Stage 1: Blowflies lay eggs around body openings.
• Stage 2: Larval activity attracts other insects (beetles, flies, mites), leading to the involvement of multiple insect species in decomposition.
• Stage 3: Larvae become pupae, and other insects, including beetles, contribute to the decomposition process.
• Stage 4: Soft tissues diminish, attracting other insects, contributing to the final stages of decomposition.

This quiz covers various types of evidence utilized in criminal investigations. You'll explore concepts like motive, opportunity, and different categories of evidence such as class, individual, and direct evidence. Test your knowledge on the principles that guide forensic analysis and evidence collection.