Behind the Yellow Tape: On the Road With Some of America's Hardest Working Crime Scene Investigators by Jarrett Hallcox, Amy Welch

an ROV might catch a glimpse of poor Natalee somewhere in the murky depths of the ocean. The St. Louis County investigators declined, however, because too much time had elapsed by then, and they knew their involvement would unfortunately be frivolous.
    Underwater crime scene investigation is in its infancy. A lot of what is studied, including how bodies move in the water and how they decompose, is mostly conjecture. For instance, whenever you hear about someone falling into water, the experts come out and pontificate on where to begin the search for the body. Invariably, the thought is that “they move with the current, so we’d better look downstream.” Then the body isn’t found. Psychics show up pointing in all directions, while others clamor for a pig to be killed and tossed into the water to see where it ends up. But drowning is a very violent death. A victim will brutally thrash about, struggling for air, and a dead pig, believe it or not, cannot mimic that movement.
    Almost always, a body will be found very near the point of entry. More often than not, when a body is not found near the point of entry, eyewitness error is to blame because the person pointed to an incorrect location. The trauma of seeing someone falling into and getting lost in a body of water is hard on the memory. The general rule of thumb is that a body will drift only about one foot horizontally for every foot it falls vertically in the water. There, the body will fall to the bottom and remain—at least for a while.
    As a submerged body decomposes, it fills with gas, just as it will on land. In water, these phases of filling with gas have come to be known as reflotation intervals . The first interval is when the bacteria in the digestive tract cause the abdomen to extend and fill with gases (the bloat stage). This traditionally occurs between twenty-four and seventy-two hours after death. During this interval, the body will bob to the surface, float with the current awhile, and then, if undisturbed, sink back to the bottom until the second interval. The second interval occurs when the bacteria in other parts of the body (the tissues, muscles, etc.) begin to give off gases. Once this occurs, the body will typically start to float again. But none of this is an exact guide. Many variables go into these calculations, including the victim’s last meal, the temperature and depth of the water, and even the body mass index we all love so much—meaning that fat people float more readily and are more likely to be found than skinny people are. Just another thing to keep in mind as you pull into the drive-through at Mickey D’s.
    The traditional means of underwater body recovery, and the way it is still done nearly everywhere today, is simply known as drag and dive . That is, get a boat, throw out a hook, and drag the bottom of the water. At the same time, divers go into the water and look around. Submerged bodies are never able to be recovered in “position found,” as at a normal crime scene, because they have been disturbed during their discovery and recovery. Yet with an ROV, for the first time it’s possible to find a body undisturbed.
     
    The guys in St. Louis County had set up all of their equipment for us, their ROV and their sonar, in the conference room to let us observe them. Then they fired up a laptop computer and showed us tapes of something we’d never before seen—an actual body recovery by an ROV.

    St. Louis County Sheriff’s Office, Minnesota, ROV Team.
HALLCOX & WELCH, LLC
    Wintertime in Minnesota means playtime on the lakes. And it is not much different from playtime in sunny Florida. But whereas Floridians drive onto their beaches to go fishing, Minnesotans drive right onto their frozen lakes and cut holes in the ice to fish. And instead of piloting Sea-Doos, they drive their snowmobiles all around the frozen waters. But the danger in Minnesota is exponentially worse. A couple of years ago, some guys put inner tubes around