HemoSpat News

Eugene Liscio of AI2-3D put together a neat video on how to use HemoSpat to estimate the impact angle of a bullet. This technique might be useful at a scene if you only have one bullet defect for a trajectory and it has a well-formed ellipse.

Why does this work? As explained in Wong and Jacobson’s article on Angle of Impact Determination from Bullet Holes, the same principles of calculating the alpha angle for bloodstains apply to bullet holes. Because the same principles are being applied, it’s important to note that as a ellipse’s alpha angle approaches 90°, the error increases dramatically [1], so you would only use this technique for impact angles ~60° or less. Bullets may deform on impact and/or deform the target surface, so this must be considered as well.

Since Eugene put together this video, HemoSpat has been modified to make this technique a little bit easier (see version 1.7.3). The calculation of the alpha angle is no longer dependent on the location of the impact being set (as Eugene does in the video). So you can just load the image and use the ellipse tool right away to get an alpha angle.

Eugene didn’t show it here, but if you do a complete analysis by adding the impact’s location, using the scale tool, and adding a plumb-line along with the ellipse, HemoSpat will allow you to visualize the (linear) bullet trajectory in its 2D views and export it to a 3D format for integration into 3D models.

Update 25 July 2016: I collaborated with the Ottawa Police Service and the Ontario Provincial Police to create some high-speed videos of bullets striking different surfaces at varying angles. These show in detail ellipses being created by bullets.

[1] Willis, C., Piranian, A. K., Donaggio, J. R., Barnett, R. J., and Rowe, W. F. Errors in the estimation of the distance of fall and angles of impact blood drops, Forensic Science International (2001) 123:1–4.

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FORident Software is pleased to announce the release of HemoSpat v1.7 for Mac OS X 10.6-10.8 [64-bit Intel], Windows XP, Windows Vista, and Windows 7.

This release includes a new project wizard, more options for the 2D viewer, new and improved exporters, and several new tutorials focused on working with point clouds.

There are many other changes and fixes as well. For download links and a more complete list of changes, please see the release notes.

HemoSpat - New 2D Viewer Options

HemoSpat – New 2D Viewer Options
HemoSpat data integrated with a point cloud using CloudCompare

HemoSpat data integrated with a point cloud using CloudCompare
HemoSpat data integrated with a point cloud using CZ Point Cloud

HemoSpat data integrated with a point cloud using CZ Point Cloud

Special thank you to Eugene Liscio of AI2-3D and the University of Toronto Mississauga Forensic Science program for their help with the point cloud work. We would also like to thank Anna Ristau and Derik White at The CAD Zone for working with us to make the Crime Zone tutorials possible.

As always we look forward to hearing your feedback and suggestions!

Shooting Incident Reconstruction Course 2013 Omaha, NE, USA

Last month I had the opportunity to attend the Bevel, Gardner, & Associates Shooting Incident Reconstruction (SIR I) course in Omaha Nebraska, USA. It was hosted by the Douglas County Sheriff’s Office and taught by Jonathyn Priest and Iris Dalley.

The course was a week long and was made up of attendees from across the US (and two of us representing Canada). It was a very interesting course and I learned a lot! It included a good mixture of classroom instruction, range instruction, and labs/workshops.

In the classroom we took apart cartridges and shotshells to examine the components of different types of ammunition, learned how to process and document a shooting scene, learned the concepts of trajectory analysis and got some hands-on experience with it, and learned about gunshot residue (GSR), stippling, wound tracks, and other topics related to wound dynamics.

Shooting Incident Reconstruction - S&W 40 Cal. Cartridge

Shooting Incident Reconstruction – S&W 40 Cal. Cartridge
Shooting Incident Reconstruction - Remington 12 Guage Shotshell

Shooting Incident Reconstruction – Remington 12 Guage Shotshell
Shooting Incident Reconstruction - Trajectory Rod Workshop

Shooting Incident Reconstruction – Trajectory Rod Workshop

We spent some time on the range to observe the effects of different types of weapon on various substrates (plate glass, laminated glass, wood, etc), examined ricochets off metal, wood, and and sand, analyzed a mock scene on a car with several bullet defects, and learned about wound dynamics through the shooting of a pig carcass with a handgun, a rifle, and a shotgun.

Shooting Incident Reconstruction - Bullet Holes In Glass

Shooting Incident Reconstruction – Bullet Holes In Glass
Shooting Incident Reconstruction - Shooting A Car On The Range

Shooting Incident Reconstruction – Shooting A Car On The Range
Shooting Incident Reconstruction - Bullet Ricochet Off Car Hood

Shooting Incident Reconstruction – Bullet Ricochet Off Car Hood

I look forward to learning more about Shooting Incident Reconstruction and how it relates to my current work in Bloodstain Pattern Analysis.

Thanks to Michael Maloney and Jonathyn Priest of Bevel, Gardner, & Associates for organizing things for me!

A few weeks ago I had the opportunity to work with some of the bloodstain pattern analysts (BPAs) in my area. Staff Sgt. Gord Lefebvre of the Ontario Provincial Police (OPP) had approached me to see if we could get together to go over some of the features of HemoSpat. He arranged some space for us at the Canadian Police College (CPC) here in Ottawa to run an impact pattern workshop.

I know some other BPAs in the area, so I invited them to join us. We ended up with analysts from the OPP, Ottawa Police Service, and the Service de Police de la ville de Gatineau. The goal of the workshop was to create an impact pattern with multiple non-orthogonal surfaces, document it, analyze it with HemoSpat, and finally to go over the export capabilities to work with the data in 3D.

We placed a box in a corner and covered it with paper and placed cardboard on the floor.

CPC Bloodstain Workshop - Setup

CPC Bloodstain Workshop – Setup

Gord suited up and created a pattern with one blow of a hammer close to the floor. Ugo Garneau (Ottawa), Vince Brideau (Gatineau), and Rob Lamarche (OPP) helped with stain selection and documentation, while Gord took the photographs.

When looking over the stains which were selected, one of the things that really stood out for me was the difference in quality of bloodstains on the three surfaces: the painted wall, the paper on the box, and the cardboard on the floor. Each of the surfaces interacted with the blood a bit differently.

On the painted surface, the impact of the blood resulted in well-formed edges.

CPC Bloodstain Workshop - Bloodstain On Wall

CPC Bloodstain Workshop – Bloodstain On Wall

The paper and cardboard each absorbed some of the blood and resulted in some wicking into the material. This shows how important it is for the analyst to understand the mechanisms of bloodstain formation in order to fit ellipses properly during analysis.

CPC Bloodstain Workshop - Bloodstain On Paper

CPC Bloodstain Workshop – Bloodstain On Paper
CPC Bloodstain Workshop - Bloodstain On Cardboard

CPC Bloodstain Workshop – Bloodstain On Cardboard

It was also interesting to note during analysis that using only bloodstains from the box resulted in a large standard deviation in the result. Adding in the stains from the wall and floor really tightened up the result. The final results of the analysis were quite good:

CPC Bloodstain Workshop - Impact Pattern 2D

CPC Bloodstain Workshop – Impact Pattern 2D
CPC Bloodstain Workshop - Impact Pattern 3D

CPC Bloodstain Workshop – Impact Pattern 3D

It was a very useful and productive day! Thanks to Gord for arranging things and to Ugo, Vince, and Rob for coming out, asking some good questions, and giving feedback. Special thanks to Doug Morris and Julie Goulet of the Royal Canadian Mounted Police (RCMP) who provided us with the training area at CPC.

ACSR Conference 2013 Atlanta, GA, USA

A couple of weeks ago I attended the 2013 Association for Crime Scene Reconstruction (ACSR) conference in Atlanta, GA, USA. It was a much smaller conference than the previous ones, but that meant that there were a lot more questions and discussions surrounding the presentations. All-in-all, Ross Gardner (Bevel, Gardner, & Associates) did a good job with the content of the conference, though being stuck at an airport hotel wasn’t exactly ideal…

Some highlights for me were:

Incidentally, Michael Maloney and Jon Priest from Bevel, Gardner, & Associates are offering 40-hour courses on Shooting Incident Reconstruction in Nebraska (June 2013) and Colorado (July 2013). If you’re interested, you can find details on their website.

Shooting Incident Reconstruction - Laser Trajectories

Shooting Incident Reconstruction – Laser Trajectories

The next ACSR conference is being organized by Cele Rossi (Montgomery County Sheriff’s Office) in Houston, TX, USA. It’s already taking shape and looks like it’s going to be a great lineup of talks and workshops. Hope to see you there in Feb 2014!

Andy Maloney
Lead Developer, HemoSpat