Crime Lab Lead Details Blood Stains In Lindsay & Patrick Clancy's Home

Sherri Crook is a supervisor in the crime scene response unit at the Massachusetts State Police Crime Laboratory in Lakeville. She testified in Lindsay Clancy's murder trial today (Tuesday, August 4, day 6) about her role in overseeing forensic scientists, analyzing biological fluids, and conducting bloodstain pattern analysis. She discussed various bloodstain types, such as drip stains, spatter stains, and transfer stains, and their significance in crime scene investigations. Crook also explained the documentation and testing processes for bloodstains. 07:39 types of stains "We describe them as passive stains, transfer stains, and dynamic stains." "And could you define what those are?" "Sure. So passive stains are stains where only the force of gravity is acting upon that stain. Some of the examples would be a drip stain, a flow, or a blood pool." "We have transfer stains, which are stains that are created when a bloody object or body comes into contact with another surface, transferring that stain there, we have for that we have smears or wipes." "And then for dynamic stains, dynamic stains are where a outside force has been acted upon the blood, a forceful force that has projected the blood onto a surface, either by projecting it out or compression that projects the blood out. In that case, we have projected blood patterns, arterial spurts that use that are use that term as dynamic stains." 15:32 "And how are blood stains typically documented at a crime scene?" "So there is a trained forensic scientist that is at every scene that we document as far as blood stain pattern analysis, they are trained in documenting the stains as far as a sketch. We also document them with ruler tape. We want to know how high up stains are from the floor, and we also use very small ruler tape with individual stains. That tape is used to show the size. It is then photoed by crime scene services. They'll do a faraway shot so we can get the whole information in one shot. They will do a medium and then a close up of stains so we can get the sizes of the stains. Those photos are used for documentation and reviewing when we do our exam." 18:58 "If you look at these stains, they are elliptical in shape, and they all have an extension, which we call the tail. So they are hitting the wall, and the tail is pointing in the direction that it is moving. So we have the elliptical shape, and then the extension. So they are going from a left to right in a downward direction." 20:47 "Now, were you asked to do blood stain pattern analysis on this case?" "I was." "And what did you use in terms of materials to conduct that analysis?" "I used photographs that were supplied from crime scene services. I utilized reports that were written by Maureen Hartnett, the chemist." 24:16 "From my analysis in looking at the stains, there is a couple of different things going on here, so they're the round circular stains, which are on the outside, are drip stains. So that is blood coming from a bloodletting event and going to the ground just due to gravity." 24:39 "The stains that are overlapping are considered a drip pattern. So standing there for a period of time, the blood blood is dripping due to gravity into itself, causing the overlapping stains as well as the small stains that are all surrounding it." 24:53 "Over here on the right side, there is some movement through the some of the red brown stains. Causing them to have lateral lateral determination, and so those would be smear stains. So they're originally drip stains that were smeared through." 27:42 "So the blood stains themselves were elliptical in shape. So it did give me some information. There was a a larger amount of blood, so you can see on the stains that it starts to go down the mirror. That's due to gravity, so we call that flow." 28:00 "Because they were elliptical in shape, there are two different categories that they could go into, which would be a drip stain that just landed at an angle, or an actually a spatter stain, which is a blood in flight. Because I couldn't tell the difference, but I did limit it down to either a drip stain that fell at an angle or a spatter stain that was forced onto that mirror, so I couldn't come to a definite conclusion." 29:30 "This blood stain didn't give us too much information. It was irregular in shape, so I couldn't tell exactly what it came from, but I did classify it as a transfer stain." 45:23 "So basically, all you can tell us is that something with blood on it touched that windowsill and left something with with a red brown stain on it touched that windowsill and left a red brown stain?" "Correct." 46:38 cross by Kevin Reddington 56:06 "And then you were referring to the drip marks on the mirror ..." "That would be consistent with some type of a violent movement, would it not?" "So it would be either due to gravity or due to blood in flight. So a force applied, sending that blood to land on there, or drip due to gravity."