Blood spatter analysis is at the heart of CSI and other crime shows, but how is it really done?
In this episode of Crime Insiders: Forensics, host Kathryn Fox speaks with forensic practitioner Professor Adrian Linacre, who specialises in body fluid dynamics and blood pattern analysis.
So what do the patterns tell us? Why is misting so important? How are blood patterns measured? Who does it?
Here are 3 things we learned from this chat:
1. Lots of information is not necessarily a good thing
When investigating a potential crime scene, it’s better to come in with a limited amount of information.
As Professor Adrian explains, “We really do not want too much information, because it’s so easy to bias and be told “this is what we think happened, can you see if it works”, which is the wrong way round.”
2. The smaller the spot, the greater the force
The size of a blood spatter can tell us a lot about what might have happened, as small spots indicate force.
A larger spot also travels further than a smaller spot. This might sound counter-intuitive, but it’s all about surface tension, adhesion and cohesion. Professor Adrian breaks it down for us:
3. Blood pressure doesn’t often impact blood loss
If someone’s blood pressure is very low, you might assume that they’re not going to be losing blood at the same rate as someone with high levels of adrenaline. However, that’s not often the case.
In Professor Adrian’s experience, almost all the blood found at crime scenes is actually in the veins:
So when you’re looking at blood pattern that is not arterial, blood pressure isn’t relevant.
Want to learn more? Listen to the full episode:
New episodes of Crime Insiders are available now on the free LiSTNR app