MA v Lindsay Clancy - Sherri Crook - Bloodstain Pattern Analyst - Mass State Police

Main points from the testimony of Sherri Crook, a bloodstain pattern analyst with the Massachusetts State Police Crime Laboratory, on day 6 of the Lindsay Clancy trial: Passive Bloodstains • Core Definition: Stains created when only the force of gravity acts upon the blood. • Physical Features: Typically circular in shape when falling straight down at a 90-degree angle, or pulling downward into streams on vertical surfaces. • Examples & Subtypes: • Drip Stain: A single blood droplet falling and hitting a surface due to gravity. • Drip Pattern: Overlapping stains created when a blood source remains stationary for a period of time, allowing blood to drip repeatedly into itself. • Drip Trail: A linear path of single drip stains created as the blood source moves. • Flow: A stream of blood created when an accumulation on a surface is pulled downward by gravity. • Blood Pool: An accumulation of liquid blood in one area, typically seeping directly from an injury on a stationary body. • Saturation Stain: A blood pool that seeps directly into an absorbent target surface, such as a mattress or carpet. Transfer Bloodstains • Core Definition: Stains created when a bloody object or body comes into direct physical contact with another surface, leaving blood behind. • Physical Features: Often irregular in shape, though they can sometimes directly track or mirror the physical shape of the transferring object (like a knife edge or hand). • Examples & Subtypes: • Wipe: Created when an object moves laterally through an existing blood pool or stain, altering its original appearance. • Swipe: Created when blood is taken from a wet blood source and transferred onto a clean, secondary surface. • Smear: A messy combination of swipes and wipes, often involving lateral, back-and-forth movements across a surface. • Simple Transfer/Contact: Direct contact without sliding, such as a bloody hand leaning on shingles or a windowsill. Dynamic Bloodstains • Core Definition: Stains created when an outside force other than gravity acts upon the blood. • Physical Features: The applied force projects the blood through the air, causing it to land in elliptical (oval) shapes. These stains often feature a "tail"—an extension of the oval shape that points in the direction the blood was traveling when it hit the surface. • Examples & Subtypes: • Spatter Stain: Blood flying through the air due to an applied force (such as flicking a bloody finger) and landing on a target surface. • Cast-Off Pattern: A linear series of circular or elliptical stains created when blood flies off a moving object (such as a swung hand or weapon). • Projected Pattern / Arterial Spurt: Created when blood is projected under pressure (such as from a severed artery), landing on a surface in a curvy, linear fashion. Lindsay Clancy Trial Playlist:    • MA v Lindsay Clancy - Jury Selection Day 1