Vol. 78, No. 1Ask an expert

Hand holding bullet in front of snow.

Bullets in the snow

Useful techniques for recovering evidence

Bullets often stop only a few centimetres below the snow's surface. If you can follow the streak, you can find the bullet. Credit: Cst. Jason Lewis, North Battleford RCMP Forensic Identification

When it comes time to find the critical bullet in an outdoor forensic investigation, snowy terrain can make a difficult job even harder. For the past 30 years, Dan McGill, a former Saskatchewan conservation officer, has been working on a set of uncomplicated but useful techniques to assist in recovering bullets from snowy crime scenes. He discussed these techniques with Eric Stewart, sharing the history and methodology of his research — including tips for officers who are looking for ways to improve their own bullet recovery in winter crime scenes.

What's the basis of your research?

It began with an investigation based on a complaint of someone hunting a cow moose out of season. The evidence indicated a moose had been shot and wounded. The subjects of the investigation, however, stated they had not shot at anything. Spent cartridges recovered on the road next to their vehicle were the same brand and calibre that these fellows had on their person. All of this provided sufficient grounds to seize their firearms. The four bullets recovered from the snow in this case were found along the tracks in the snow from the moose. All of the bullets recovered from the snow were matched to the two firearms seized and charges were laid as a result.

As a result of this first investigation, we — myself and Les Oystryk, a conservation officer and long-time partner with me in this research — began to realize the potential that snow had to stop bullets. However, this first bullet recovered in the snow had been slowed and the bullet shape distorted by passing through a big game animal. Fortunately, there were three other bullet marks in the snow and a visual check appeared to show the bullets may have entered the snow and stopped. In a follow-up search using a metal detector, we were able to find three more bullets in the snow.

These bullets were a different type than the original bullet and appeared to be in near perfect shape. Later on in this investigation, the RCMP firearms section successfully matched all four of the bullets recovered to the two firearms seized in the investigation. While bullet recovery and firearm matching was not new, the potential for the recovery of bullets from snow-covered fields was. It was apparent to us there was an opportunity to find more such bullets at similar crime scenes. Getting this information out to officers offered significant value, but we realized we first had to do some research on the matter before this idea was ready to be shared.

Initially, the research was intended to explore a few basic questions. Firstly, to estimate the likelihood of recovering bullets fired from high-power rifles of differing calibres at different distances into snow-covered fields in a condition useable for forensic purposes. The second goal was to develop dependable bullet-recovery methods using readily available tools and instruments.

Our hope was to be able to share the research and field work with other enforcement agencies and officers as valuable forensic knowledge. We also felt we needed to convince law enforcement that bullets do actually stop in snow and can be recovered. We are simply lucky to have snow-covered fields as a perfect medium that allows for this type of evidence to be gathered.

How has it evolved in the past 30 years?

We suspected from the results of the initial field study that a layer of crusted snow tended to deflect the bullets and reduce the chances for bullet recovery. As the initial field test was conducted in the early spring, where repeated freezing and thawing of the snow was likely to result in a buildup of crust on the snow, a second field test was conducted with mid-winter snow conditions, more typical of the hunting season. This second field test provided results showing more dependable recovery methods and generally higher rates of bullet recovery. Many of the bullet marks in the softer snow conditions also showed how the bullets were either fishtailing or tumbling and leaving both wide and narrow marks in the snow, doubtlessly shedding a great deal of energy and speed. All of this helped to track and find the area where the bullet stopped.

Over time and largely from questions asked of us at workshops that we had not yet fully considered, we began to include in training relatively basic but essential explanations of the effect of gravity on bullets — concepts such as a bullet travelling at high speed dropping to the ground at the same rate as a bullet dropped out of a person's hand, and also explanations of how the viscosity of snow can be expected to slow and stop a bullet.

How do you train members to apply these techniques?

We use a combination of theory and practice. We first spend a morning in the classroom showing the concepts, science and demonstrating proven recovery techniques. Afterwards, using shooting ranges set up with a range of bullet types, members are set up in small groups with each group taught the connection between primary observation skills — looking for typical indicators in the snow, how to read these marks and how important dealing with shadowy or snow-blinding conditions can be — and then how to use a metal detector or to search by hand to find bullets or bullet fragments. The power of determination and patience in working such a vast crime scene is also critical thinking that we transfer to the students. And all of this offers an opportunity to demonstrate and train students on some of the aspects of photographing bullet recovery evidence while locating these bullets. At times, all of this is done under very challenging and very realistic field and weather conditions.

The success of the training has been its incorporation into the Resource and Environmental Law program of Saskatchewan Polytechnic in Prince Albert, Sask. The training is designed for students working toward a career as a conservation officer. These sessions have included RCMP officers. Overall, it has provided an important opportunity for all involved.

What kinds of investigations can benefit?

Simply, any type of investigation — criminal or otherwise — involving situations where bullets may have entered snow. Importantly, our experience has also shown a logical connection to other evidence — for instance, the number of shots fired, the number of different firearms used or the locations shots were fired from which may also lead to the recovery of shell casings.

What are the basics police should learn about recovering bullets in snow?

The recovery method could be described simply as following the marks left in the snow by the bullets and if the bullet stops within a reasonable distance, use a metal detector to recover it from the snow. With bullets, of course, there can be a variety of paths each will take. One bullet in the first field study was found in perfect condition lying on top of the snow about 450 meters downrange and this was done by following the skip marks it left on top of the snow. However, in most cases where bullets are recovered, the bullet leaves a shallow streak in the snow before dropping below the surface and stopping, usually within two metres from where it first touched the snow — and often only a few centimetres below the snow's surface.

With this level of predictability, the recovery method starts with assessing the scene for likely locations of evidence and finding any streaks in the snow made by the bullets. Next, we mark each bullet streak, with a second mark downrange to show the direction of the bullet's travel as well as an indication of the location the bullet was fired from. Using these marks, we examine the scene to judge if the bullet has stopped or continued on downrange. Finally, we look for the mark that indicates a bullet has entered the snow and stopped. From there, the bullet can be located by searching with a metal detector.

The bullet marks in the snow often lead to other evidence beyond the bullet itself — for example, spent casings, shoe prints, tire tracks and locations where shots were fired, among others.

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