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IAI SP5 practice questions

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Question 1Bloodstain Pattern

In bloodstain pattern analysis, what does the term 'angle of impact' describe?

  1. The angle at which a weapon strikes bone
  2. The angle between the blood droplet's flight path and the target surface Correct answer.
  3. The temperature-dependent viscosity angle of blood
  4. The angle between two intersecting blood trails

Explanation

The angle of impact is defined as the acute angle formed between the trajectory of a blood drop and the plane of the surface it strikes. It governs how elongated the resulting stain becomes, with lower angles producing more elliptical stains. It is not a measure of weapon motion or stain-to-stain geometry.

Question 2Bloodstain Pattern

A bloodstain is circular with no visible directionality. What does this most likely indicate about the drop's impact?

  1. It was produced by a secondary spatter event
  2. It struck the surface at a very shallow angle
  3. It was deposited by contact transfer
  4. It struck the surface at approximately 90 degrees Correct answer.

Explanation

A near-circular stain indicates that the drop struck the surface perpendicular (about 90 degrees) to the plane, so it spread equally in all directions. As the angle decreases, the stain becomes progressively more elliptical. Circularity alone does not indicate transfer or a specific spatter mechanism.

Question 3Bloodstain Pattern

Which bloodstain pattern type is characterized by a central blood pool surrounded by a ring of smaller satellite stains radiating outward?

  1. Expirated spatter
  2. Cast-off pattern
  3. Drip pattern with satellite spatter Correct answer.
  4. Impact spatter

Explanation

When blood drips vertically onto a surface, the primary stain may be surrounded by smaller satellite stains thrown outward on impact; this is a drip pattern with satellite spatter. Impact spatter arises from a force applied to liquid blood, not from a single falling drop. Cast-off results from blood flung from a moving object.

Question 4Bloodstain Pattern

What is the primary mechanism that produces a cast-off bloodstain pattern?

  1. Blood flung from a bloody object as it changes direction or stops Correct answer.
  2. Blood projected by a gunshot muzzle blast
  3. Blood expelled from the nose and mouth during breathing
  4. Blood forced from a wound by arterial pressure

Explanation

Cast-off patterns form when blood is flung from a blood-bearing object, such as a weapon, as it swings and then decelerates or reverses direction. The resulting stains typically line up in a linear trail. Arterial, expirated, and gunshot mechanisms produce different pattern characteristics.

Question 5Bloodstain Pattern

A fine mist-like pattern of very small droplets is found near a body with a gunshot wound and a soot ring on the skin. Which pattern is most consistent with these findings?

  1. High-velocity impact spatter from the gunshot Correct answer.
  2. Low-velocity drip pattern
  3. Arterial spurt pattern
  4. Transfer pattern from a bloody hand

Explanation

Gunshot wounds commonly produce a fine forward spatter of very small droplets often described as high-velocity impact spatter, and the soot ring supports a close-range discharge. Drip, transfer, and arterial patterns do not normally generate this fine mist combined with soot.

Question 6Bloodstain Pattern

What is the 'area of origin' in bloodstain pattern analysis?

  1. The location where a victim's body was first found
  2. The point where a blood trail terminates
  3. The three-dimensional point from which blood was projected Correct answer.
  4. The surface on which the largest stain appears

Explanation

The area of origin is the three-dimensional region in space from which blood droplets were projected, estimated by back-projecting the trajectories of individual stains. It is distinct from the two-dimensional area of convergence on a surface. Neither refers to body discovery or trail endpoints.

Question 7Bloodstain Pattern

Which of the following is a defining characteristic of an expirated bloodstain pattern?

  1. Stains arranged in a straight linear trail
  2. Stains that form only on vertical surfaces
  3. Stains frequently mixed with bubbles or mucus from the airway Correct answer.
  4. Stains that are always perfectly circular

Explanation

Expirated patterns are produced when blood is expelled from the nose or mouth by air pressure, so they often contain air bubbles, mucus, or diluted blood. They can appear on many surface orientations and are not defined by circularity or a linear trail.

Question 8Bloodstain Pattern

A stain is 12 mm long and 6 mm wide. Using the width-to-length ratio method, what is the approximate angle of impact?

  1. 30 degrees Correct answer.
  2. 15 degrees
  3. 60 degrees
  4. 45 degrees

Explanation

The sine of the impact angle equals the width divided by the length, so sine equals 6/12 = 0.5. The inverse sine of 0.5 is 30 degrees. The other values correspond to different ratios and would not match this stain.

Question 9Bloodstain Pattern

What distinguishes a transfer bloodstain pattern from a spatter pattern?

  1. Transfer patterns always contain satellite stains
  2. Transfer patterns only occur on fabric
  3. Transfer patterns require an airborne droplet to strike a surface
  4. Transfer patterns form when a blood-bearing object contacts a surface and leaves an imprint or smear Correct answer.

Explanation

Transfer patterns are created by direct contact between a blood-bearing object and a receiving surface, producing imprints, swipes, or smears. Spatter patterns, by contrast, involve airborne droplets produced by force. Transfer is not restricted to fabric and does not depend on airborne droplets.

Question 10Bloodstain Pattern

A void pattern (a clean area surrounded by bloodstains) on a wall most likely indicates what?

  1. That an object or person blocked blood deposition at that location Correct answer.
  2. That the wall was cleaned after the event
  3. That the stains are expirated
  4. That blood was projected perpendicular to the wall

Explanation

A void is an area free of bloodstains surrounded by staining, typically created when an object or person absorbed or blocked the blood that would otherwise have reached the surface. It can help reconstruct the position of an object or individual during the event. Cleaning, perpendicular projection, and expiration do not specifically create voids.

Question 11Bloodstain Pattern

In estimating the area of origin, why is it important to use stains with well-defined impact angles from multiple directions?

  1. Because intersecting trajectories from varied directions triangulate the three-dimensional source Correct answer.
  2. Because stains at 90 degrees cannot be used
  3. Because the largest stain always marks the origin
  4. Because a single stain can determine the origin exactly

Explanation

Back-projecting strings or lines along the trajectories of drops from several directions allows the analyst to triangulate the three-dimensional point of origin. A single stain yields only one line and cannot locate a point in space. Stains near 90 degrees are actually useful because their direction is reliable.

Question 12Bloodstain Pattern

A series of parallel, elongated stains increasing in size along a line is most consistent with which pattern?

  1. A pool of blood
  2. An expirated pattern
  3. A cast-off pattern from a swinging weapon Correct answer.
  4. A transfer smear

Explanation

Cast-off patterns appear as linear arrays of stains that may increase in size along the direction of the swing as more blood is flung. The parallel alignment and progressive size change reflect the arc and acceleration of the bloody object. Pools, expiration, and transfer smears do not produce this linear array.

Question 13Bloodstain Pattern

What is the significance of 'satellite stains' in a drip pattern?

  1. They form only on non-porous surfaces
  2. They indicate arterial bleeding
  3. They prove the blood is human
  4. They are small droplets thrown outward when a larger drop impacts a surface Correct answer.

Explanation

When a falling drop strikes a surface, secondary droplets can be ejected outward and land around the primary stain, forming satellite stains. Their presence supports a drip mechanism but does not identify the species of blood or the specific vessel injured. They can form on porous and non-porous surfaces alike.

Question 14Bloodstain Pattern

A bloodstain appears on a ceiling directly above a victim. Which mechanism best explains this deposition?

  1. Blood projected upward by an impact or arterial pressure Correct answer.
  2. Transfer from a bloody hand touching the ceiling
  3. Gravity-driven dripping from a wound
  4. Expiration while lying supine

Explanation

Blood deposited on a ceiling generally requires an upward projection mechanism, such as impact spatter or arterial spurt, because gravity-driven dripping and expiration would deposit downward. Transfer would require direct contact with the ceiling. Ceiling staining therefore supports an active projection event.

Question 15Bloodstain Pattern

Which factor most directly affects the size of droplets produced in impact spatter?

  1. The color of the blood
  2. The age of the bloodstain
  3. The amount of force applied to the blood source Correct answer.
  4. The ambient humidity only

Explanation

Greater force applied to liquid blood generally produces smaller droplets, while lower force yields larger droplets. Droplet size is therefore used cautiously to infer the energy of the event. Color, humidity alone, and stain age are not the primary determinants of droplet size.

Question 16Bloodstain Pattern

An analyst observes a swipe pattern on a wall. What does this indicate?

  1. An object moved through wet blood and contacted the wall Correct answer.
  2. Blood dripped vertically onto the wall
  3. Blood was expelled from the airway
  4. Blood was projected by a high-energy impact

Explanation

A swipe occurs when a blood-bearing object or a bloody surface moves across a surface that may or may not already be bloody, producing a smeared, directional deposit. It reflects motion and contact rather than projection or dripping. Impact, drip, and expiration produce different morphologies.

Question 17Bloodstain Pattern

What is the area of convergence in bloodstain pattern analysis?

  1. The location of the largest single stain
  2. The three-dimensional point of blood origin
  3. The two-dimensional point on a surface where trajectory lines intersect Correct answer.
  4. The boundary of a blood pool

Explanation

The area of convergence is a two-dimensional location on a surface found by drawing lines through the long axes of stains and noting where they intersect. It is used as a step toward estimating the three-dimensional area of origin. It is not itself a point in space or a measure of stain size.

Question 18Bloodstain Pattern

A bloodstain pattern on a shirt shows a series of fine, high-velocity droplets concentrated around a bullet hole. What does this most likely represent?

  1. A drip pattern from a bloody nose
  2. Forward spatter away from the entry wound
  3. Back spatter directed toward the shooter or source Correct answer.
  4. A transfer pattern from folding the shirt

Explanation

Back spatter consists of blood and tissue propelled back toward the source of the force, often depositing fine droplets on nearby surfaces such as a shooter's clothing or a weapon. Forward spatter travels in the direction of projectile movement. The concentration around a bullet hole with fine droplets supports back spatter rather than transfer or dripping.

Question 19Bloodstain Pattern

Which characteristic best distinguishes arterial spurt patterns from impact spatter?

  1. Arterial spurts form only on ceilings
  2. Arterial spurts show a repeating, gushing distribution linked to cardiac rhythm Correct answer.
  3. Arterial spurts always contain mucus
  4. Arterial spurts consist only of fine mist droplets

Explanation

Arterial spurt patterns reflect the pulsatile nature of bleeding, producing gushing or spurting stains that may repeat with each heartbeat. Impact spatter instead arises from an applied force and typically radiates from a point. Arterial patterns are not defined by fine mist, ceiling location, or mucus.

Question 20Bloodstain Pattern

A stain measures 20 mm long and 10 mm wide. Which angle of impact is most consistent with this measurement?

  1. 45 degrees
  2. 20 degrees
  3. 60 degrees
  4. 30 degrees Correct answer.

Explanation

The impact angle is the inverse sine of the width-to-length ratio, here 10/20 = 0.5, which yields 30 degrees. This calculation assumes an elliptical stain measured along its major and minor axes. The other angles correspond to different ratios.

Question 21Bloodstain Pattern

During reconstruction, an analyst finds that trajectory lines from stains on two adjoining walls converge at a point in the room. What does this most directly establish?

  1. The area of convergence in three dimensions
  2. The identity of the weapon used
  3. The area of origin in three dimensions Correct answer.
  4. The time of death

Explanation

When trajectory lines from stains on multiple surfaces are projected into space and intersect, the intersection estimates the three-dimensional area of origin. The area of convergence is the two-dimensional surface intersection that precedes this step. Weapon identity and time of death cannot be established from trajectory geometry alone.

Question 22Bloodstain Pattern

An analyst observes stains with tails pointing consistently in one direction on a vertical surface. What can be inferred?

  1. The blood was projected at an angle, and the tails indicate the direction of travel Correct answer.
  2. The stains are transfer imprints
  3. The stains were deposited by simple vertical dripping
  4. The blood was expirated from the airway

Explanation

On a vertical or inclined surface, a drop striking at an angle produces a stain with a tail pointing in the direction of the drop's travel. Consistent tail orientation across many stains indicates the overall direction of projection. Vertical dripping, transfer, and expiration do not produce consistent directional tails of this kind.

Question 23Bloodstain Pattern

Why must an analyst exercise caution when using droplet size alone to classify an impact as low, medium, or high velocity?

  1. Because droplet size is never measurable
  2. Because overlapping mechanisms can produce similar droplet sizes, and classifications are descriptive rather than definitive Correct answer.
  3. Because velocity cannot be estimated in any way
  4. Because blood never forms droplets

Explanation

Droplet size ranges for low, medium, and high velocity overlap, and different mechanisms can yield similar sizes, so size alone is not a definitive classifier. Modern practice treats these categories as descriptive energy ranges rather than rigid thresholds. Droplet size is measurable and blood does form droplets.

Question 24Bloodstain Pattern

A pattern shows both fine high-velocity droplets and larger drip stains overlapping on the same surface. What is the most defensible interpretation?

  1. The pattern results from a single event with a single mechanism
  2. The larger stains are always the most recent
  3. Multiple deposition events or mechanisms likely contributed to the pattern Correct answer.
  4. The fine droplets are irrelevant artifacts

Explanation

Overlapping patterns of different morphologies usually indicate more than one deposition event or mechanism, such as an impact followed later by dripping. Reconstructing sequence requires careful analysis of overlap and drying. A single mechanism is unlikely to produce both fine mist and large drips, and larger stains are not automatically the most recent.

Question 25Bloodstain Pattern

Which statement best describes the limitation of back-projecting straight lines to estimate an area of origin?

  1. It requires no measurements
  2. It always locates the origin exactly
  3. It assumes straight-line trajectories and ignores gravity and air resistance effects Correct answer.
  4. It can only be applied to transfer patterns

Explanation

Stringing or back-projecting trajectories assumes droplets traveled in straight lines, but gravity and air resistance curve the paths, introducing uncertainty. The method also depends on accurate angle measurements and stain selection. It does not apply to transfer patterns and cannot guarantee an exact origin.

Question 26Crime Scene

Under the IAI Crime Scene Certification framework, which term describes the documented, unbroken record of who handled an item of physical evidence and when?

  1. Scene integrity seal
  2. Contamination baseline
  3. Chain of custody Correct answer.
  4. Evidence triage

Explanation

Chain of custody is the chronological documentation of seizure, custody, control, transfer, and disposition of evidence. It establishes that the item presented in court is the same item recovered at the scene and has not been altered or substituted.

Question 27Crime Scene

A crime scene investigator photographs an item, then collects it, then photographs the empty location where it had been. What is the primary purpose of the final photograph?

  1. To document that the item was removed and record its original position Correct answer.
  2. To show the item's original orientation relative to the body
  3. To provide a close-up of any latent prints on the surface
  4. To demonstrate the photographer's calibration standard

Explanation

A post-collection photograph documents that the item was removed and preserves a visual record of exactly where it had been situated. It supports later reconstruction and rebuts claims that evidence was moved or planted.

Question 28Crime Scene

Which type of bloodstain pattern is created when a blood drop strikes a surface at an angle, producing a stain with a distinct direction of travel?

  1. Satellite
  2. Splash
  3. Pool
  4. Cast-off Correct answer.

Explanation

Cast-off stains are produced when blood is flung from a moving object such as a weapon, yielding linear stains whose shape and distribution indicate direction of travel. They are distinct from passive pools and from satellite spatter around a primary drop.

Question 29Crime Scene

When establishing an initial perimeter at a homicide scene, what should the first responding investigator do before entering the scene?

  1. Collect the weapon and package it
  2. Secure and control access to the area Correct answer.
  3. Interview all witnesses and record statements
  4. Sketch the layout of the room

Explanation

The priority is to secure the scene and control access so that evidence is not lost, altered, or contaminated. Witness interviews, collection, and sketching follow once the scene is stabilized and protected.

Question 30Crime Scene

Which item is most appropriately collected as a control or reference sample at a scene where a suspect bled?

  1. A sample of the victim's clothing
  2. A swab of the suspect's known blood Correct answer.
  3. A photograph of the stain
  4. A scraping of the wall near the stain

Explanation

A known reference sample from a specific individual is required for comparison with questioned biological stains. Without a known sample, DNA or serological results cannot be attributed to a particular person.

Question 31Crime Scene

Which packaging method is appropriate for a bloodstained, air-dried cotton shirt collected at a scene?

  1. Submerged in a preservative solution
  2. Sealed in an airtight plastic bag
  3. Placed in a paper bag or envelope Correct answer.
  4. Wrapped in aluminum foil and sealed

Explanation

Dried biological evidence should be packaged in breathable paper so moisture can escape and microbial degradation is limited. Airtight plastic can trap moisture and promote mold and DNA degradation.

Question 32Crime Scene

Which of the following is a recognized function of a crime scene sketch prepared by an investigator?

  1. Recording measurements and spatial relationships of evidence Correct answer.
  2. Replacing photographs in the final case file
  3. Providing a chemical analysis of collected samples
  4. Establishing the legal chain of custody

Explanation

A sketch captures measured distances and the relative positions of items, supporting reconstruction and courtroom explanation. It complements photographs rather than replacing them and does not perform custody or analytical functions.

Question 33Crime Scene

During a scene walk-through, an investigator notices a footprint in loose soil. What is the most appropriate immediate action?

  1. Step beside it and photograph it with a scale before casting Correct answer.
  2. Brush away loose soil to reveal the full print
  3. Pour water to stabilize the soil
  4. Lift the print with tape

Explanation

The print should be documented in place with photographs and a scale before any casting or lifting. Preserving the original context and avoiding disturbance protects the evidentiary value of the impression.

Question 34Crime Scene

An investigator must decide whether a recovered firearm should be unloaded at the scene. Which approach best reflects accepted practice?

  1. Leave it loaded and never document its condition
  2. Disassemble it fully to count remaining cartridges
  3. Always unload it immediately with bare hands
  4. Make it safe only when necessary and document any manipulation Correct answer.

Explanation

Firearms should be made safe when necessary for safety or transport, and any manipulation must be documented because it can alter the evidentiary condition. Unnecessary handling or disassembly risks loss of trace evidence and creates documentation gaps.

Question 35Crime Scene

Which factor most directly threatens the integrity of biological evidence recovered from a warm, humid environment?

  1. Excessive chain-of-custody paperwork
  2. Number of investigators present
  3. Use of a measuring scale in photographs
  4. Ambient humidity promoting microbial degradation Correct answer.

Explanation

Warm, humid conditions accelerate microbial growth and enzymatic degradation of DNA and other biological material. Prompt drying and breathable packaging mitigate this risk.

Question 36Crime Scene

A latent print is developed on a nonporous surface using cyanoacrylate fuming. Which subsequent step is typically required to visualize the developed print?

  1. Immersing the item in water
  2. Washing the surface with detergent
  3. Heating the item to 200 degrees Celsius
  4. Applying a fluorescent or powder dye stain Correct answer.

Explanation

Cyanoacrylate fuming deposits a white polymer on the print, which is then enhanced with a contrasting powder or fluorescent dye stain for visualization and photography. Heat, detergent, or water would damage the developed print.

Question 37Crime Scene

Which statement correctly distinguishes class characteristics from individual characteristics in physical evidence?

  1. Class characteristics require DNA analysis to establish
  2. Individual characteristics are found only in biological evidence
  3. Class characteristics can associate evidence with a group; individual characteristics can associate it with a single source Correct answer.
  4. Class characteristics are always more discriminating than individual characteristics

Explanation

Class characteristics place an item in a category such as a shoe size or paint type, while individual characteristics are features that can be linked to one specific source. Individual characteristics carry greater evidentiary weight for identification.

Question 38Crime Scene

At a scene, an investigator finds a spent cartridge case on carpet near a body. What is the most appropriate collection technique?

  1. Spray it with luminol before collection
  2. Lift it with forceps or gloved fingers and package it in a paper envelope Correct answer.
  3. Pick it up with bare fingers and drop it in a plastic bag
  4. Vacuum the carpet and submit the entire vacuum bag

Explanation

Cartridge cases should be handled minimally and packaged in breathable material to preserve latent prints and trace evidence. Bare-hand handling risks contamination and loss of fingerprint detail.

Question 39Crime Scene

Which measurement practice best supports later reconstruction of a bloodstain pattern on a vertical wall?

  1. Recording the distance from a fixed reference point and the angle of impact Correct answer.
  2. Estimating distances by eye and noting them later
  3. Collecting the wall section without measurements
  4. Photographing only the entire room from the doorway

Explanation

Accurate reconstruction requires measured distances from fixed reference points and documented angle-of-impact data. Eyeball estimates and incomplete documentation undermine the geometric analysis courts rely on.

Question 40Crime Scene

What is the primary reason for wearing gloves and changing them between evidence items at a scene?

  1. To comply with uniform regulations
  2. To protect the investigator from chemical burns
  3. To prevent transfer of DNA and trace material between items Correct answer.
  4. To improve grip on tools

Explanation

Gloves protect evidence from the investigator's own DNA and from cross-transfer of material between items. Changing gloves between items limits contamination that could mislead laboratory interpretation.

Question 41Crime Scene

An investigator is documenting a scene where a door was forced. Which combination of evidence types is most relevant to reconstructing the forced entry?

  1. Toolmarks, paint transfer, and door frame damage Correct answer.
  2. Soil samples and insect activity
  3. Latent prints and footwear impressions only
  4. Bloodstain patterns and DNA only

Explanation

Forced entry reconstruction relies on toolmarks, transferred paint or material, and physical damage to the door and frame. These class and individual characteristics can link a tool to the damage.

Question 42Crime Scene

Which practice best preserves the evidentiary value of a questioned document found at a scene?

  1. Placing it in a clear plastic sleeve and handling it minimally Correct answer.
  2. Stapling it to the case file
  3. Writing notes directly on the document
  4. Handling it with bare hands and folding it for storage

Explanation

Documents should be handled minimally and protected in a clear sleeve so latent prints and paper characteristics are preserved. Bare handling, folding, writing on, or stapling can introduce or destroy evidence.

Question 43Crime Scene

Which is the most appropriate first step when an investigator arrives at a scene where a body is present and a strong odor of decomposition is noted?

  1. Immediately move the body to a cooler
  2. Cover the body with a plastic sheet
  3. Open windows to ventilate the room
  4. Document the scene and note environmental conditions before disturbance Correct answer.

Explanation

The scene and its environmental conditions should be documented before any disturbance, because temperature and conditions affect estimates of time since death. Moving the body, ventilating, or covering it prematurely alters the evidence.

Question 44Crime Scene

Which statement about the role of a crime scene investigator in court is most accurate?

  1. The investigator must defer all testimony to the laboratory analyst
  2. The investigator testifies to observations, methods, and chain of custody Correct answer.
  3. The investigator may offer opinions on legal guilt
  4. The investigator may summarize witness credibility

Explanation

Testimony should focus on what the investigator observed, the methods used, and the documented custody of evidence. Opinions on guilt or witness credibility exceed the investigator's role.

Question 45Crime Scene

Which sequence correctly reflects the general order for processing a scene after it has been secured?

  1. Documentation, collection, assessment, search
  2. Assessment, documentation, search, collection Correct answer.
  3. Search, collection, assessment, documentation
  4. Collection, documentation, search, assessment

Explanation

Processing generally begins with assessment and planning, then documentation of the scene as found, a systematic search, and finally collection and packaging. Collecting before documentation risks losing context.

Question 46Crime Scene

An investigator must document a small, dark stain on dark fabric where color detail is hard to capture. Which photographic approach is most appropriate?

  1. Use oblique lighting or an alternate light source with appropriate filters Correct answer.
  2. Rely on a verbal description without a photograph
  3. Photograph only in total darkness
  4. Use a direct flash at maximum power

Explanation

Oblique lighting or an alternate light source can reveal contrast that direct flash obscures, and appropriate filters enhance the stain's visibility. Documenting such detail photographically preserves evidence that may later be consumed by testing.

Question 47Crime Scene

A suspect's clothing is recovered and must be examined for both DNA and latent prints. Which handling consideration is most critical?

  1. Wash the clothing before analysis
  2. Package the clothing in plastic to preserve moisture
  3. Coordinate examination order to prevent one analysis from destroying the other Correct answer.
  4. Cut out only the stained areas and discard the rest

Explanation

Different examinations can consume or alter evidence, so the order must be planned, often beginning with non-destructive techniques. Coordination among analysts preserves the maximum evidentiary value.

Question 48Crime Scene

An investigator finds a footwear impression in a shallow layer of dust on a hard floor. Which method is most appropriate for recovering it?

  1. Photographing without any recovery attempt
  2. Casting with dental stone
  3. Electrostatic dust print lifter Correct answer.
  4. Lifting with adhesive tape

Explanation

An electrostatic dust print lifter is designed to recover impressions in dust on hard surfaces without destroying them. Casting is suited to impressions in soil or snow, and tape lifting is better for residues on certain surfaces.

Question 49Crime Scene

Which situation best illustrates a break in the chain of custody that could affect admissibility?

  1. An item is transferred between two officers with a signed entry
  2. An item is left unattended in an unlocked vehicle for several hours Correct answer.
  3. An item is sealed and initialed by the collecting officer
  4. An item is stored overnight in a locked evidence locker with a log entry

Explanation

Leaving evidence unattended in an unlocked vehicle creates an undocumented gap in control that can support challenges to authenticity. Proper transfers, locked storage, and sealed initialed packaging maintain the record.

Question 50Crime Scene

A scene contains a suspected arson. Which observation is most relevant to determining the area of origin?

  1. The number of furniture items in the room
  2. The owner's insurance policy details
  3. Char depth and burn patterns indicating direction of fire spread Correct answer.
  4. The color of the walls before the fire

Explanation

Fire investigation uses char depth, burn patterns, and related indicators to determine the direction of spread and the area of origin. Pre-fire appearance, furnishings count, and insurance details do not directly establish origin.