Criminal Investigation

Estimating time of death

Algor Mortis - body cooling (1.5 degrees per hour). Ocular changes - cloudiness of cornea (2-4 hours eyes open, 12-24 closed). Stomach contents. Rigor Mortis - muscle stiffening (10-15 hours to begin, remains rigid for 24-36 hours). Livor Mortis - lividity (starts 30 minutes to 2 hrs, fixed at 8 to 12 hrs). Cadaveric spasm. Decomposition.

Six means of identifying a deceased body

Fingerprints, dentition, DNA printing, scars/marks/tattoos, anatomical abnormalities, identification/jewelry/clothing.

5 most common wounds in death investigations

Firearm, incised, stab, puncture, lacerations.

Specific behaviors in detecting deception

Lack of emphasis in hand behaviors, swearing to truthfulness of assertions, rogatory position.

Rules of evidence

Proof - combo of all facts in determining guilt or innocence. Testimony Admissibility Relevance and materiality (importance of evidence) Competence of evidence and competence of witnesses Weight of evidence Presumptions (conclusive and rebuttable) Inferences Burden of proof Burden of going forward Order of proof - corpus diliecti Judicial notice The hearsay rule Evidentiary Privileges

5 basic search patterns

Spiral - rarely used strip/line - not excessively large grid - not excessively large zone/quadrant -used for significant size pie/wheel - rarely used

Impression Evidence

Surface Impressions 3D Impressions -3 feet of tire track

Biometrics

The measurement and analysis of unique physical or behavioral characteristics (as fingerprint or voice patterns) especially as a means of verifying personal identity.

forensic palynology

the use of pollen and spore evidence to help solve criminal cases

3 major scientific systems of biometric-based identification

1. Anthropometry (physical measurements). 2. Dactylography (finger prints). 3. Deoxyribonucleic acid typing (DNA).

Four crime scene search considerations

1. Boundary determination. 2. Search pattern. 3.instruction of personnel. 4. Coordination.

Classification of threats

1. Direct. 2. Indirect. 3. Veiled threat. 4. Conditional threat.

Objectives of criminal investigations

1. Discover the truth 2. Establish a crime was actually committed 3. Identify and apprehend the suspect 4. Recover stolen property 5. Assist in the prosecution of the person charged with the crime.

6 main guidelines for field notes

1. Listen attentively. 2. Intervene if speaker is losing focus. 3. Review specifics with person. 4. Allow time for person to consider the info you have stated to verify and correct. 5. Add or correct info if needed. 6. Verify all changes with speaker.

5 fundamental rules of crime scene investigator

1. Maintain control. 2. Conceptualize events. 3. Proceed with caution. 4. Apply inclusiveness. 5. Maintain documentation.

Crime scene investigation objectives

1. Overall coordination of the scene. 2. Forensic services. 3. Investigative services.

Elements of robbery

1. Taking 2. Carrying away of 3. Personal property of 4. Another with 5. Intent to deprive the victim permanently by 6. The use of fear, force, or threat of force.

Signature Samples

15 to 20 required in same page

Elements of an incident report

Accuracy and clear communication of the meaning that the writer intended.

Bullying and cyberbullying

Aggressive behavior or intentional harm by an individual or group repeated over time that involves an imbalance of power. Cyber is using Internet, cellphone, or technology to harass.

First rule of evidence.

Anything is admissible as evidence unless there is a rule that prohibits its admissibility.

Delay in arraignment rule

Arrest of a person must be taken before a committing magistrate "without unnecessary delay". McNabb vs. US

Characteristics of ideal poisoning for suicides

Being odorless, tasteless, and colorless. Being readily soluble. Having a delayed onset. Being undetectable. Low dose lethality. Easily obtained and not traceable. Chemically stable.

Class vs. Individual characteristics

Class is physical evidence that are common group of objects or persons (shoes, hammer). Individual can be identified with a high degree of probability as originating with a particular person or source.

Collecting hair standards

Collect at least 30 hairs from various parts of the head. Half pulled and other half combed. If attached to object, send object. If object is too big use clean tweezers. Combed and pulled hairs packaged separately.

Proof

Combination of all those facts (evidence) in determine the guilt or innocence of a person accused of a crime.

CRAVED - theft hot products

Concealable Removable Available Valuable Enjoyable Disposable

Two types of presumptions

Conclusive - one that the jury must follow without alternatives. (Finding or beyond reasonable doubt) Rebuttal - specific conclusion be drawn unless that conclusion has been dispelled or rebutted by evidence presented to the jury for its consideration. (Presumption if innocence or sanity)

Free and voluntary rule

Confessions are voluntary and free from coercion including physical and psychological threats. Brown vs. MS.

Exceptions to hearsay rule

Confessions, admission, spontaneous/excited utterances, dying declaration, former testimony (prelim testimony). Must prove voluntariness and trustworthiness.

Three different types of firearm injuries related to distance

Contact, close (less than about 18 inches), distant (greater than 18 inches).

GSR facts

Contains antimony, barium, and lead from primer. On hands for 3 hours, face for 8 hours, nasal for 48 hours. Don't handcuff to rear or fingerprint.

Three broad categories of evidence

Corpus delicti (elements of a crime), associative (bidirectional, connects victim and suspect or scene), tracing (identification of suspect).

Traumatic brain injuries in children

Coup-Contrecoup injuries or blunt force, Shaking baby syndrome.

Documentation of a crime scrne

Crime scene entry log, administrative log, assignment sheets, photographic logs, rough sketch, offense report, evidence recover log, EMT log, lifted-prints log, search warrant.

3 important development issues on children to know in investigation.

Development level equal to children same age. Level in regard to sexuality. Ability to respond adequately to interviews and to testify.

Entomology - 2 ways to determine time since death with insects

Dipteran larval development and insect succession over time.

Types of evidence

Direct, real (physical), demonstrative (illustrative), circumstantial, opinion.

Four Objectives of Investigative Process

Establish a crime was committed. Identify and apprehend suspect. Recover stolen property. Assist in the prosecution of the person charged.

Rule of inclusiveness

Every available piece of evidence be obtained and where there is a question as to whether a particular item constitute evidence be defined as such.

Action, physical, situational stereotyping.

Expectations set to see one thing. Robber will look like a particular type. Previous experiences with and knowledge of a particular location increases vulnerability.

Reasons for problems with children who participate in criminal proceedings.

Immaturity age. Unique attributes in relationship with suspect. Our limited understanding of children's capabilities as witnesses.

Three categories of tool marks

Impressions Scrapes Pinching/shearing

Inductive vs. Deductive reasoning

Inductive moves from specific details to a general view, factual situation of a case to form a unifying and logically consistent explanation. Deductive creates a hypothesis about the crime.

Abduction patterns

Infants - emotion based or maternal desires. Preschool aged - sexually motivated and profit based. Middle school - most common, sexually driven. High school age - profit and emotion based.

Three essential ingredients of arrest

Intention, authority, custody.

Investigative Services

Interviewing witnesses. Conducting and documenting canvas Field interrogation of suspect if in custody Carrying out and recording vehicle canvas

Berghuis vs. Thompkins

Invocation of Miranda rights must be clear and unambiguous to be effective. David vs. US allowed interview to continue after ambiguous statement of "maybe I should talk to a lawyer".

Types of Homicides

Justifiable- necessary killing of another person in performance of a legal duty or the exercise of a legal right when the slayer was not at fault. Excusable- differs from justifiable that the one who commits homicide is to some degree at fault but the degree of fault is not enough to constitute a criminal homicide. Misadventure and self-defense.

Four objectives of an interrogation

Obtain valuable facts, eliminate the innocent, identify the guilty, obtain a confession.

4 classes of photographs

Orientation (long/large), relationship (medium), identification (close-ups), comparison.

Munchausen Syndrome by Proxy

Parent or caretaker attempts to elicit medical attention for self by injuring or inducing illness in a child.

Three types of latent prints

Plastic prints (3D, molded or impressed into some pliable surface). Patent/contaminated/visible prints (foreign matter like ink l, blood, dust). Latent/visible (unseen or hidden)

Three requirements of a witness in an interview

Presence, consciousness, attentiveness.

Primary objectives responding to bank robbery

Public safety, officer protection, tactical control of scene.

Blood Collection

Purple top for blood sample. Two tubes with EDTA. Don't freeze. Keep in cooler with ice packs. Dried blood - cotton swab with distilled water. Air dry. Keep portion of swab free of blood for control. Package in envelope with sealed corners. Don't use airtight containers. Water/Snow - collect from thickest concentration of blood and clots. Eliminate as much snow as possible. Freeze in airtight container.

Major mapping methods

Rectangular coordinates - best where scenes have clear and specific boundaries like interior walls. Triangulation Baseline coordinates - should not exceed 30 feet Polar coordinates Grid system - large outdoor scene without significant features or landmarks.

situational child molester types

Regressed - poor coping skills, motivation is substitution, any available victim, coercion. Morally indiscriminate- user of people, picks vulnerable and opportunistic, lures and forces, sadomasochist. Sexually indiscriminate- sexual experimentation, boredom, new and different victims, hugely likely to have porn collection. Inadequate- social misfit, insecure and curious, non threatening victim, exploits.

Types of burns on children

Scald Burns - spill/splash, immersion. Contact Burns.

Uses of child pornography

Sexual arousal. Lower child inhibitions. Blackmail. Medium of exchange. Profit.

Child pornography vs. Child erotica

Sexually explicit reproduction of a child's image (photos, videos). Erotica is any material relating to children that serves a sexual purpose for a given individual (toys, games, drawings, books).

Glass evidence - gunshot

Side opposite of initial impact will be a characteristic cone-shaped area. Radios fracture - lines move away from point of impact. Concentric fracture - circle the same point.

Factors that limit persons ability to identify

Significance of event, length of period of observation, lack of ideal conditions, psychological factors internal to the witness, physical condition, lack of familiarity with members of another race, expectancy.

Child molestation types

Situational (regressed, morally indiscriminate, sexually indiscriminate, inadequate) and preferential (seduction, introverted, sadistic).

Two major components off criminal law

Substantive criminal law - elements that describe and define a crime. Procedural criminal law - what can and cannot be done with people.

Conditions affecting latent prints

Surface (porous, non porous, semi porous), nature of material contaminating print, any physical or occupational defects of person making print, how the object on which the prints appear was handled (smear), amount of contamination.

Crawford v. Washington (2004)

The use at trial of out of court statements made to police by an unavailable witness violated a criminal defendant's Sixth Amendment right to confront witnesses against him.

Four methods of developing latent prints

Traditional powders, fluorescent powders, chemicals, superglue fuming.

Maryland vs. Shatzer

Two week separation from Miranda rights on follow up interview.

Comparison sample types

Unknown or questioned samples -recovered sample whose source is unknown. -questioned evidence may have been transferred to an offender during commission of crime. -evidence from unknown or questioned source that can be linked to multiple offenses. Known samples -standard or reference -control or blank -elimination sample

Attachment of Jeopardy

Usually starts once a jury has been sworn.

Three types of false confessions

Voluntary, coerced compliant, coerced internalized.

Arrest situations

Warrant has been issued, crime committed in presence of arresting office, PC to believe that suspect has committed a felony, statutorily created instances.

Blood from Snow or Water

Water - recover sample from the thickest concentrations of blood and clots. Snow - eliminate as much snow as possible from the sample. Freeze it in a clean, airtight container, and submit ASAP to lab.

Legal search and seizures

When a warrant has been issued, consent, incident to an arrest, a motor vehicle, exigent circumstances exist, conduct an inventory.

Three styles of robbery

ambush - unplanned selective raid - minimum planning, scores are low to moderate. planned operation - larger scores, careful planning, no planned use of force.

ACE-V for fingerprints examiners

analysis, comparison, evaluation, verification