Crime Scene Investigations Midterm

This study set covers all PowerPoints learned: - Intro to Crime Scene and Documentation - Crime Scene Photography - Crime Scene Sketching - Utilization of Drones - Evidence Collection and Packaging - Fingerprint Processing - Trace and Biological Evidence

What are the roles and responsibilities of a CSI?

Document, search and identify evidence, collect and process evidence, package and preserve evidence, prepare written reports, and testify in court

So, you get to the crime scene, now what?

1. scene briefing and walkthrough

2. initial observations and notes

3. search for evidence

4. Develop a plan

5. photograph location and visible evidence

6. identify and mark visible evidence

7. photograph marked evidence

8. sketch

9. evidence collection

10. evidence processing

11. on-scene debriefing and final walkthrough

What do you do after you finish at the scene?

1. go back to the office

2. do any additional processing and packaging of the evidence

3. submit the evidence

4. complete documentation

What must you use to determine the best way to process a crime scene?

Your training, education, and CRITICAL THINKING

What are some everyday challenges you may encounter when processing a scene?

weather (wind, rain, extreme cold, and extreme heat), sights and smells, securing the scene, physically challenging location to process, mentally challenging, and emotionally challenging

What are the everyday rules for being a CSI?

1. never make assumptions

2. there is always more to learn

3. be prepared for anything

4. they can't do it right in the lab, if we don't do it right in the field

5. critical thinking

What are the different types of crime scene documentation?

Notes, photographs, sketches/3D scans, reports

Should each type of documentation be able to stand alone?

Yes, but each should also complement the other types of documentation

What is the purpose of documentation in crime scene investigation?

permanently records the scene/evidence, records what you did at the scene, used as a tool for the CSI to prepare for court, it is admitted into court, and allows for additional analysis in the future

When arriving at the scene, what is the first thing you should do?

Meet with the investigator and gather/confirm the following:

- every investigator's information

- offense type

- date/time/location of occurrence

- case number

- victim and suspect information

What notes should you write down while at the scene?

- what happened

- any changes to the scene before your arrival

- what you observed on scene

- what you did on scene

- what someone else did on scene (if applicable)

- description/orientation of the victim's body and/or injuries

- any information that dictates why you did or did not do something

- any additional information regarding anything pertinent on scene

How should you draft your report?

Use your field notes as a reference (not everything has to be included), remember who the report is for (don't use unnecessarily big words), think of it as a narrative (you're telling a story)

What information should be included in your report?

Case information, who you met with and what was advised, what items were observed and recovered on scene, what services were rendered by you/other personnel

What is included in the case information?

case number/run number, date of occurrence, offense, request time/dispatch time, arrival time/departure time, primary investigating officer, on-scene officer, responding technician's information, victim's information, and suspect's information

What is crime scene photography?

It is a form of crime scene documentation that accurately reports what is seen in a fair and unbiased manner.

True or False: Cases can be strengthened and won on photographic evidence

True

True or False: Cases can be weakened and lost on photographic evidence

True

What is the first image that should be taken at every scene?

Photo identifier (includes case number, offense, date, and photographer's name)

When should a photograph of the photo identifier be recorded a second time?

when information regarding the case changes (example: robbery to homicide)

What are the two types of photographs?

Documentary (majority of crime scene) and evidentiary (used for comparison purposes)

What is the purpose of overall photographs?

Document the scene as YOU found it and overlap photos (corner to corner method or wall to wall method)

What is the purpose of midrange photographs?

it further establishes the location of evidence and it captures a landmark with the item

What is the purpose of close-up photographs?

Detail evidence/damage/injury at scene

How do you take a close-up photograph?

Have an appropriate scale present, photo is shot at 90 degrees, fill the frame with the subject, and take a picture of at least one side.

When are evidence markers placed down at the crime scene?

After the initial overall photographs are taken

What is the succession of photographs?

1. Photo identifier

2. "AS IS" overall, midrange, close-up photographs

3. Place evidence markers

4. Overall, midrange, close-up photographs with evidence markers

What are the two factors that make a successful crime scene photograph?

1. creating a well-balanced and compelling composition

2. setting a correct exposure

What is exposure?

Amount of light reaching the sensor

What are the variables that directly affect exposure?

Aperture, shutter speed, and ISO

What is the diaphragm of the camera?

Set of blades which can be opened to let more light through the lens or closed to restrict the light entering the camera

What is the aperture?

- Size of the resulting diaphragm opening

- smaller aperture = less light = greater depth of field

- larger aperture = more light = less depth of field

What is the f/stop?

Fraction relating to the size of the aperture opening to the lens being used

What is the best depth of field for crime scene photographs?

f/22, f/16, f/11, and f/8

What is the shutter speed?

- Length of time the shutter curtains are open allowing light to pass

- larger number = FASTER shutter

- smaller number = SLOWER shutter

- also controls motion

What is the ideal shutter speed for crime scenes?

1/60

What is ISO?

- The camera sensor's sensitivity to light

- Higher ISO = more exposed image = more noise

What is the ideal ISO for crime scene photographs?

100, 400, and 800

What are the different exposure modes?

- manual exposure: you set the f/stop and shutter speed

- program exposure: the camera automatically sets the f/stop and shutter speed

- aperture priority: you set the f/stop, the camera automatically sets the shutter speed

- shutter priority: you set the shutter speed, the camera automatically sets the f/stop

What are the different flash techniques?

- direct flash: flash directly on the subject

- bounce flash: flash is directed onto some other surface

- use of diffuser: attached to the flash and reduces the amount of light

- off-camera flash: flash can be held at any angle/position

- fill flash: hard flash utilized when there's sunlight creating shadows to fill the whole scene with light

What is available light photography?

It shows the original lightening at the time of the incident and/or while the CSI are on scene; typically used on night scenes and taken without flash

How do you take photographs of living victims and suspects?

You can take their pictures on scene, at a hospital, or at a police station. You need overall, midrange, and close-ups of all four sides of the person and document any injuries they may have. Show them kindness and respect.

How do you take photographs of deceased people?

Begin by taking overall, midrange, and close-up photographs, ensuring to get their face, chest, and back. Photograph injuries, signs of decomposition, and anything that may have been removed from the victim (jewelry, pocket contents, etc.)

How do you take exterior vehicular photographs?

If on scene, take overall photographs of the vehicle in its surroundings, and photographs of all four sides of the vehicle. Also take close-ups of the license plates, VIN number, and any damages.

How do you take interior vehicular photographs?

Open all doors and take photographs of each door and its compartments and take photographs of the interior from each opening. Then open the trunk and hood and take photographs. Open all compartments and take photographs, then take photographs of any damage.

True or False: All photographs must be listed on the photography log

False

What are evidentiary photographs?

They are photographs taken for further analysis, considered to be evidence after you capture it, and is taken in RAW file format

What is the purpose of evidentiary photographs?

They are used to compare a known to an unknown.

What types of evidence should you take evidentiary photographs of?

Fingerprints, tire/footwear imprints, tool marks, bite marks, transfer patters, and pattern injuries

What camera settings should evidentiary photographs have?

RAW file format and JPEG, low ISO, high f-stop

What equipment is necessary to take evidentiary photographs?

Camera, external camera flash, PC cord, tripod, reference scale (L shaped), and macro lens

What are the procedures for taking evidentiary photographs?

1. Take documentary photographs to document location

2. Place reference scale on the same plane as the impression

3. Place an evidence identifier somewhere on the reference scale

4. Mount the camera to the tripod

5. Attach the macro lens to the camera

6. Adjust the camera settings and file format correctly

7. Connect the flash to the camera using a PC cord

8. Place the assembled camera and tripod over the evidence

9. Ensure camera lens is at a 90-degree angle

10. Fill the frame!

11. Use the disconnected flash to take photographs with different angles of light.

What is oblique lighting?

A light source that is directed directly across the surface of an object at various angles.

What is oblique lighting used for?

It is used for photographing impression evidence because it creates a 3D effect by casting shadows at various angles.

What is crime scene sketching?

It is another form of crime scene documentation that provides:

- directional orientation

- measurements

- different viewpoints

- shows relationship of evidence items to location and to each other

- easier to see everything together at one time

- can exclude irrelevant items

When should you perform a sketch?

- homicides

- shooting

- police-involved incidents

- questionable deaths

- upon detective request

- when YOU think it's necessary

What are the categories of sketches?

rough sketch and final sketch

What is a rough sketch?

completed on scene using pencil and paper or an iPad, can sometimes be sloppy/hard to read, must make permanent prior to submission, contains all necessary measurements, and can be seized by court

What is a final sketch?

computer generated, much neater, can use a simplified design with a legend, and used in court

How do you make a sketch?

1. Observe the scene and plan the sketch

2. Outline the area

3. Locate and draw objects/evidence within the sketch

4. Take measurements

5. Include pertinent information on the sketch

What are the different types of sketches?

Overview/Floor Plan/Bird's eye, elevation, and exploded/cross projection

What is an overview/floor plan/bird's eye?

Most common method, horizontal plane depicted, top-down view of the crime scene, easy to visualize the entire area

What is an elevation sketch?

vertical place is depicted, great for bloodstains or bullet holes in a wall

What is an exploded/cross-projection sketch?

combination of the bird's eye and exploded view (horizontal AND vertical planes; walls laid flat), useful to show relationships between evidence on two adjacent surfaces

What are the different measuring methods?

rectangular coordinates, triangulation, and baseline

What are rectangular coordinates?

- utilizes a fixed landmark

- measurements are taken at 90-degree angles to the fixed landmark

- utilized on indoor and outdoor scenes with clear and specific boundaries

What is triangulation?

uses two reference points, measurements are taken at angles from reference points to item, indoor and outdoor scenes but best for specific measurements

What is baseline measuring?

utilizes a straight line, used when no landmarks exist on scene, place tape measure in a straight line within scene, document one end of tape to a known landmark, measurement are taken at a 90-degree angle to the baseline tape measure

What is the different measuring equipment?

tape measure, walking tape, and laser measuring device

How do you measure a scene?

interval measuring (measuring device is reset after measurement taken of object) and continual measuring (each item/area is measured back to a common reference point

What do you measure at a scene?

- Exterior (street, sidewalk, vehicle, etc.)

- Interior (walls, windows, doors, etc.)

- Victim location (measure head, feet, and arms)

- Evidence markers

What must be included in a sketch?

case information, important areas/items, key, orientation indicator, dimensions of the scene, "not to scale"

What must be true of a sketch for it to be admissible in court?

- must be fair and accurate representation of a scene

- must be relevant to the point at issue

- verbal testimony must support the sketch by the person who made it or someone present during completion

What is a 3D scanner?

Non-contact device that captures millions of discrete data points to measure an object or space using laser infrared technology; produces a detailed 3D image in minutes; allows the scene to be immortalized FOREVER

What is considered a drone?

An unmanned aircraft weighing less than 55 pounds on takeoff, including everything that is on board or attached to the aircraft.

Who regulates the use of drones?

The Federal Aviation Administration (FAA)

What do you need to fly a drone?

Drone operators operating under Part 107 must obtain their Remote Pilot Certification (must pass the aeronautical knowledge exam)

What are rules and regulations that pertain to drone operations?

• All aircrafts under 55 lbs must be registered with the FAA

• Must fly only in uncontrolled airspace

• Must keep aircraft in sight (visual line-of-sight)

• Must fly under 400 feet above ground level (AGL)

• Must yield right of way to maned aircrafts

• Must use anti-collision lighting during nighttime flights

• Must NOT fly over people

What is aerial photography?

Capturing of images from an elevated view

What is photogrammetry?

Utilizing drone photographs to create a 3D model of the scene, in which measurements can be derived

What are four types of evidence?

• Testimonial evidence: witness statements

• Demonstrative evidence

• Circumstantial evidence

• Real/Physical evidence: real, tangible items

What is Locard’s Principle?

Every contact leaves a trace; creates a linkage between victim, suspect, and crime scene

What is the value of physical evidence?

• Prove a crime has been committed and/or establish key elements of a crime

• Establish identity of persons associated with the crime

• Place the suspect in contact with the crime or crime scene

• Exonerate the innocent

• Corroborate the victim’s testimony

• May be more reliable than eyewitness testimony

• The absence of physical evidence (NEGATIVE EVIDENCE) may provide useful information

What are class characteristics?

Properties of physical evidence that may be common to several items; used to eliminate not identify

What are Individual characteristics?

Unique properties that can be attributed to one common source'; can be used to eliminate and/or identify

How do you search indoor scenes?

Search entirety of the room from least intrusive to most intrusive (THINK OUTSIDE THE BOX)

Make sure you have a search warrant and document it

How do you search outdoor scenes?

Always search a bit further last the last found item of evidence and look under and on vehicles

What are the different search methods?

Zone search, lane search, grid search, spiral search, metal detector, K9

What do you collect at a burglary scene?

• tools used to gain entry/exit

• shoeprints/fingerprints/swabs on handled items

What do you collect at a robbery scene?

• Robbery note

• weapon left behind

• bottles/cups/cans

• fingerprints/swabs on handled items

What do you collect at an arson scene?

• ignitable liquid sample

• gas can/Molotov cocktail

• fingerprints/swabs on handled items

What do you collect at a rape/sex offense scene?

• condom

• clothing

• bottles/cups/cans

• fingerprints/swabs on handled items

What do you collect from a shooting scene?

• firearm/cartridge cases/projectiles

• clothing

• bottles/cups/cans

• fingerprints/swabs on handled items

What is collected first at a scene?

Any transient/fragile evidence to avoid loss of evidence or contamination (from weather, items around body, areas less secured)

True or False: Evidence is typically collected BEFORE you start processing the scene for latent fingerprints.

True

What are the different collection methods?

• collect the entire item

• swabbing

• cuttings

• liquid samples

• tweezers

• trace evidence lifter

• scraping

What do you package the evidence in?

paper bags/envelopes (NO PLASTIC)

How are firearms and knives/sharps packaged differently?

They are placed in a cardboard box using zip ties to secure them in the box.

Where are swabs placed?

Small swab boxes to ensure DNA does not degrade

What is arson evidence stored in?

Metal paint cans

What is the purpose of the chain of custody?

Used to prove that the evidence being admitted in court is the same evidence that was originally collected at the scene