Science & STEM

Blood Spatter Test: Practice Forensic Pattern Analysis

Moderate2-5mins

This blood spatter test helps you practice reading drops, spines, and angles so you can interpret impact patterns with confidence. Use it to spot study gaps before a lab, class, or exam and get instant results. To round out your skills, review motion and force in our basic physics quiz, build core knowledge with biology multiple choice questions, and refresh lab terms with a phlebotomy practice test.

Start Quiz
Paper art style red blood spatter shapes on sky blue background with bold quiz title text
25Questions
InstantResults
FreeAlways
DetailedExplanations
Take the Quiz
1Which pattern best indicates blood expelled under pressure from a breached artery?
2A bloodstain is 6 mm long and 3 mm wide. The angle of impact is approximately arcsin(width/length).
3On a rough surface like unfinished wood, what feature commonly forms around the main droplet due to disruption of its edges?
4The spine of a bloodstain refers to which part of a drop?
5Expirated blood often contains which distinguishing feature?
6Which presumptive test turns pink in the presence of blood due to peroxidase-like activity?
7A void pattern suggests an object blocked blood deposition, leaving a clean area outlining the object's shape.
8Which best distinguishes a wipe from a swipe?
9Back spatter in firearm events most commonly travels toward the shooter from the entrance wound.
10Which feature helps determine the direction of travel of an elongated droplet?
11Which observation supports expirated blood rather than impact spatter?
12Point of origin in 3D is located where the back-projected trajectories intersect above the point of convergence.
13Which factor most increases satellite formation around impact stains?
14Luminol reacts with the iron in hemoglobin to produce blue chemiluminescence in the dark, but it can yield false positives with some oxidants.
15Which statement about drying time of bloodstains is most accurate?
16Which describes skeletonized transfer?
17Fly artifacts can mimic impact spatter but often show what distinguishing trait?
18Area-of-origin reconstruction assuming straight-line trajectories ignores droplet air drag and can overestimate height for shallow angles.
19Which environmental factor most risks false positives with luminol at a scene?
20Gunshot back spatter can be drawn into the muzzle or intermediate spaces, producing so-called blowback.
Learning Goals

Study Outcomes

  1. Understand blood and blood spatter fundamentals -

    Learn the core principles of blood and blood spatter analysis, including pattern types, terminology, and their forensic relevance.

  2. Identify arterial blood spatter characteristics -

    Recognize the unique features of arterial blood spatter to distinguish high-pressure spurts from other bloodstain patterns.

  3. Analyze 90 degree blood drop -

    Examine the shape and diameter of circular drops to determine perpendicular impacts and reconstruct crime”scene events.

  4. Apply angle of impact calculations -

    Use the angle of impact practice answer key to measure bloodstain trajectories and calculate impact angles accurately.

  5. Interpret spines definitions in forensics -

    Understand how spines form on bloodstains and what their presence reveals about the dynamics of bloodshed.

  6. Evaluate quiz performance for targeted skill improvement -

    Review your results against the practice answer key to identify strengths and focus on areas needing further study.

Study Guide

Cheat Sheet

  1. Angle of Impact Calculation -

    Master the formula θ = arcsin(width/length) to determine the angle of impact for blood drops on flat surfaces. For example, a drop with a width of 2 mm and length of 4 mm yields θ = arcsin(0.5) ≈ 30°, a method endorsed by the International Association for Identification. Mnemonic: "Sine Size over Side" helps recall width ÷ length.

  2. Spines and Satellites Identification -

    Differentiate spines (elongated projections) from satellites (small secondary droplets) to infer force and directionality. Spines definition forensics guides you in mapping impact direction by following the tail of each spine away from the target. Research in Forensic Science International shows high-velocity impacts produce more satellites.

  3. Arterial Blood Spatter Patterns -

    Recognize spurting patterns from arterial injuries, characterized by continuous, wave-like droplets. These patterns correlate to systolic pressure, with an average wave frequency of 60 - 100 pulses per minute, providing clues to timing and victim position. Case studies on arterial blood spatter (Journal of Bloodstain Pattern Analysis) highlight distinct color variation during oxygenation cycles.

  4. 90-Degree Blood Drop Analysis -

    At a perfect 90° angle, blood drops form nearly perfect circles - measure diameter directly for volume estimation. Practice with the angle of impact practice answer key: if diameter is 5 mm, the droplet volume approximates 0.06 mL per established forensic tables. Tip: Use graph paper beneath samples to confirm circularity quickly.

  5. Surface Texture Effects -

    Account for target texture: rough surfaces increase spatter irregularity, producing scalloped edges and more satellites. Smooth, non-porous targets (e.g., glass) yield cleaner ellipses, easing length/width measurements. According to FBI Laboratory guidelines, always document substrate type before analysis to avoid interpretive errors.

Explore More

Other Sciences Quizzes

Lab Safety QuizMeniscus Graduated Cylinder Quiz - Avoid Parallax ErrorMETAR QuizMuscle Origin and Insertion QuizOSHA Needlestick Prevention Quiz - Sharps Safety TrainingEntomology Quiz for Science Olympiad
AI-DraftedHuman-Reviewed
Reviewed by
Michael HodgeEdTech Product Lead & Assessment Design SpecialistQuiz Maker
Updated Feb 20, 2026