Officers get forensics training

A couple dozen first responders and crime scene investigators gathered around a makeshift crime scene Wednesday afternoon in Jackson.

Jackson Sun : 31.12.2016

They watched instructors spatter blood on a large sheet of paper taped between the floor and the wall at the Madison County Fire Department, but other blood marks on the paper and a nearby shirt and pair of pants were either faint or not visible at all.

What followed was arguably the afternoon’s big highlight, and all it took was a flip of the light switch and a few sprays from a bottle.

An instructor sprayed a blood finding agent called Bluestar Forensic over the clothes and paper, instantly revealing blue prints where blood had dried.

“Wow,” one said.

“Crazy,” said another.

And though not every scene calls for such a blood finding product, its potential usefulness required no explanation – especially considering it doesn’t mess up DNA.

The session was part of a one-week class put on by the UT Law Enforcement Innovation Center and affiliated with the National Forensics Academy.

The UT LEIC travels around the state and elsewhere to teach officers how to recognize blood stain patterns and use photography and other tools to better understand crime scenes — and hopefully find answers that lead to justice. Dan Anselment, a training consultant, has worked with UT since 2014. He previously lived in Minnesota.

“I grew up in a family of law enforcement, and there is something about the challenge to crime scenes, trying to figure out who did this, why did they do it, what evidence is there,” he said. “I enjoy trying to figure out and find clues that maybe others won’t necessarily see, so for me it’s definitely a challenge but it’s something that I like to be a part of.

“And also it’s rewarding; it’s very rewarding. If you can successfully help bring closure to a family, a victim of a crime, because of your work that you do out at a scene, I mean that’s invaluable.”

Earlier in the afternoon trainees placed drops of blood on a sheet of paper, with the resulting spots differing in shape depending on the angle. The session also covered the different ways blood can be spread around at a scene, and what each pattern might suggest about what happened. One trainee asked if such a demonstration might ever be used in court, but the instructors explained it’s unlikely a judge would allow it. A recreation attempt in a controlled setting would be possible, but it’s difficult to do and wouldn’t necessarily help a case.

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Officers get forensics training

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Photographing bloodstains

July 7, 2016

Photographing bloodstains: Bluestar reagent FORENSICS 4 AFRICA 07.07.2016 (Nick Olivier) In the late summer of 2012, police officers in a small Midwestern town were called

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Photographing bloodstains

Photographing bloodstains: Bluestar reagent

FORENSICS 4 AFRICA 07.07.2016 (Nick Olivier)

In the late summer of 2012, police officers in a small Midwestern town were called to the scene of a homicide. The caller reported that they had explored the creek in a wooded area at the north end of town and found a deceased man weighed down by rocks in the creek.

The victim had significant neck injuries that appeared to be consistent with a large, sharp weapon. Further examination of the area revealed a trail of blood about 20 metres long which led to a large pool of blood in a homeless camp next to the stream.

Dr. Tim Wilson – Associate Professor and Chair Department of Criminal Justice – Missouri Southern State University

Police located a machete between two trees near the blood trail. Investigators did their best to document the blood trail in daylight; however, due to the length of the trail, they were unable to show it in its entirety. Investigators returned to the scene after dark in an attempt to obtain a photograph of the blood trail using Bluestar Forensic Latent Bloodstain Reagent, a luminol-based blood visualization chemical that causes blood traces to luminesce.

The process of photographing bloodstains at an outdoor crime scene requires several important pieces of equipment and adequate personnel in order to capture the luminescence after the chemical has been applied, while at the same time illuminating the scene adequately so that the viewer can appreciate the composition of the crime scene. This list includes:

  • DSLR camera with a minimum f / 3.5
  • Tripod
  • Shutter release cable or remote control (for extended shutter times required)
  • One or more external flashes
  • Bluestar Forensic Latent Bloodstain Reagent, at least two vials of prepared solution in spray bottles
  • Sufficient staff to operate the camera, flashes and sprayers

There are several factors regarding the use of a DSLR in low light scenes that should be kept in mind when using this technique. Firstly, the camera settings should be set to the widest possible aperture and the lens should be in manual focus mode – otherwise, in near total darkness, the camera will attempt to focus by emitting light from the camera’s LED, which in turn can ruin the image. Secondly, a tripod and cable release or remote shutter release should be used in an effort to eliminate the movement of holding the camera by hand or even pressing the shutter for an extended period of time. In this case, as the scene was located in a wooded ravine with very little ambient light and no moon, the final exposure required a time lapse of 255 seconds. Without the tripod and cable release, the image would probably have been blurred due to camera movement. Before starting the exposure, make sure your focus is correct by illuminating the scene with a light source.

Secondly, in a large outdoor scene like this, the use of external flashes is necessary to illuminate the area beyond what a single flash could show. Bear in mind that it is best for those using the flashes to ensure that they are out of sight of the camera. The required flashes can be activated at any time during the exposure, but it is recommended that the flashes be triggered at the beginning of the exposure or at the end of the exposure to ensure that you do not illuminate the staff applying Bluestar through the sprays.

Finally, make sure that the people spraying Bluestar keep moving during the exposure for two reasons: 1) to maintain the application of the chemical, ensuring that the luminescence is visible throughout the exposure; and 2) to prevent any ambient light from illuminating them during the long exposure. In addition, several exposure tests are probably necessary to determine the correct number of flashes and the length of time the shutter should be open, given the lighting conditions of a particular scene.

Bear in mind that this technique of illuminating blood evidence should only be used to tell the story of the event, and not as evidence of a presumptive positive test for the presence of blood due to the fact that the chemical reacts with other substances, such as bleach.

All images were captured using a Canon EOS Rebel XS SLR digital camera with an 18-55mm IS lens. The scene was at the bottom of a shallow ravine in a heavily wooded area with very little ambient light other than that provided by a moonless night sky. This technique relied on darkness to allow for very long exposures, ensuring that the Bluestar luminescence would be visible until the end of the run.

Article Forensic 4 Africa
Source: Evidence Technology Magazine

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