1. What is Angle of Impact?

The angle of impact is the acute angle formed between the direction of a blood drop and the plane of the surface it strikes. It's a fundamental measurement in bloodstain pattern analysis that helps reconstruct crime scenes.

2. How Does the Calculator Work?

The calculator uses the angle of impact formula:

Where:

• \( \theta \) — Angle of impact (degrees)
• \( width \) — Short axis of bloodstain (units)
• \( length \) — Long axis of bloodstain (units)

Explanation: The more circular the stain (width ≈ length), the steeper the impact angle (closer to 90°). The more elliptical the stain, the shallower the impact angle.

3. Importance in Bloodstain Analysis

Details: Angle of impact calculations help forensic investigators determine the trajectory of blood droplets, which can reveal the position of victims or assailants during bloodshed events.

4. Using the Calculator

Tips: Measure the width (short axis) and length (long axis) of the bloodstain in the same units. Ensure width ≤ length. The calculator will return the angle in degrees (0°-90°).

5. Frequently Asked Questions (FAQ)

Q1: What's the most common angle of impact?
A: Most bloodstains in crime scenes have angles between 30°-60°, as extreme angles (very shallow or very steep) produce less stable stains.

Q2: How accurate is this calculation?
A: The formula provides a good estimate but actual angles may vary slightly due to surface texture, blood viscosity, and other factors.

Q3: What does a 90° angle mean?
A: A 90° impact angle produces a perfectly circular stain, indicating the blood drop fell perpendicular to the surface.

Q4: What's the minimum measurable angle?
A: In practice, angles below 10° are difficult to measure accurately as the stains become extremely elongated.

Q5: Can this be used for other fluids?
A: The principle applies to other Newtonian fluids, though viscosity differences may affect stain morphology.