The science of blood spatter | Forensic Files

I think what's important for us is that our viewers understand each of the terms
because we're talking about these terms in the interviews and I just want to be able to illustrate them okay when we
talk about impact spatter what does that mean impact spatter is force applied to
liquid blood so I'm going to pour some of our artificial blood here into my hand and I'm going to punch it and
that's Force going into a blood Source the force impacts the blood and the blood spatters yes and then the blood
bre breaks up into smaller drops it's impact that's one way blood gets out you can see how it's it's radiating
out we have some smaller stains with some directionality up to the top what's cast off cast is the result of a bloody
object in motion so cast off is if I keep the blood that's on my hand and I my hand like that those larger stains
are in what I would call kind of a linear fashion and they're all going you can see the directionality they're going
up the wall because when you cast off the blood it was moving in an upward Direction yes so we have cast off we
have impact what's the other stains that we were looking at what's transfer staining
so I have a bloody surface coming in contact with a nom blooded surface and then I I move my hand so it's called a
swipe it's a blooded surface with a non-bloody surface with movement and now again I can see something contacted the
wall transfer you have impact you have cast off all different ways in which blood
may end up at the scene yes and each one of these will tell a different part of the
story yes when studied properly I take the size of the pattern the overall location in the room how many stains I'm
seeing their overall distribution the average size of each of those stains all of those come into play the idea of
conducting experiments in which you might cast off blood or try to produce an impact spatter the idea of all of
that is to try to see what kind of fit there is between the stains created the spatter created and the facts of the
account that you've been presented yeah I think it's responsible to conduct experiments in in your scene
and if I can recreate it then I'm putting that as a viable option for how that blood was deposited at the scene

Forensic scientist Karen Green demonstrates potential causes of blood spatter. Evidence relating to blood spatter was key in Dr. Robert Neulander's trial for the murder of his wife, Leslie.

Brief Summary

Blood spatter analysis techniques are explained, focusing on impact spatter, cast off, and transfer staining in crime scene investigations.

Key points

Understanding Blood Stains. Explore the science behind blood spatter analysis and its significance in crime scenes.

Episode highlights

Understanding Blood StainsExplore the science behind blood spatter analysis and its significance in crime scenes.“Blood spatters tell a different part of the story.”1:55Oct 1, 2015

Episode quotes

Blood spatters tell a different part of the story.

1:55WatchOct 1, 2015

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