SCA - Class 11
Welcome back! I’m glad you could join me once again for class 11 of the Sheriff’s Citizens’ Academy.
Arriving a little early, we joined the few who were already there and waited for the rest of the class to show up. Our instructor was Detective Ed Bailey who also taught the Cyber Crimes class, so we needed no introduction.
The first part of the class was a quick review about arriving at a crime scene and the first thing you do: Take a picture. If you are taking a picture of footprints or tire tracks, you may get a better picture with different lighting than just your regular flash. You could place a flashlight on the ground and get a side lighting with it. That would make the shadows of the print much clearer. You could also set a five gallon bucket with a small hole in the top for your lens over the track, shine a bright light on the bucket and it will light up the whole thing.
“Once you have taken pictures of the tracks,” Det. Bailey told us, “you make a plaster cast of it. Usually when we go into a crime scene, after we take pictures, we will make any casts of prints before we move on to other things because the plaster has to dry. So, if we do the tracks first we can just pick them up at the end before we leave and they should be dry enough to lift.”
He showed us a few casts that had been made from a shoe print and from a tire track. He had two “sandboxes” in the front of the room filled with damp sand. “All right, everyone come up here,” he told us. Most of us had remembered to wear shoes with interesting traction, but some didn’t. First off he made a hand print in the sand. “Because I already have three casts of my shoe,” he laughed, “I guess I should have a hand print. Now, everyone make a print in one of the boxes. It’s easiest to make it along the sides. If you don’t have interesting traction, you can make a hand print.”
Soon the boxes had footprints and hand prints all along the edges of them. Next Det. Bailey mixed up a bag of plaster. (I can’t remember what the kind was.) “You are going to think this is way too watery when you mix yours up,” he informed us. He had us all feel his bag when he had mixed it up and it sure did feel watery. We watched as he carefully filled his handprint. Then it was our turn.
We each were given a bag of mix and a regular bottle of water. I thought it was quite fun to squish the bag and mix the plaster up. After I thought it was done, Det. Bailey said I needed a little more water. The next time he checked it he said was perfect. Pouring the mixture into the print was interesting. You don’t just dump it in the middle or you might mess up the track. Instead you should start to pour from the corner and let it fill up the print. You want the cast to be fairly thick so that it won’t break as easily when you remove it.
|Dad making his cast|
|Filling in my print|
Before long the boxes were filled with light colored splotches and we all returned to our seats.
“Does anyone have any questions?”
I did. “Do you take prints the same way in the snow?”
“Almost,” Det. Bailey replied. “If we poured the plaster directly into the snow, it would melt it.” So they first take a can of some aerosol and spray it into the air above the print, letting it fall down gently into the print. That hardens the snow all around it and then they pour in the plaster.
He told us of another time when he had to get really creative to take a cast of a shoe print. “Some guys broke into this unused building, went up to the second floor, climbed out a window onto the roof of the gun shop next door. Broke in and stole some guns. Well, the old building hadn’t had anyone in it for months, and the dust on the stairs was about an inch thick. Those guys left the most pristine set of footprints I’ve ever seen! The problem was, how do I lift them? We have an electrical device that lifts the dust and sometimes works to lift prints. I tried it, but all it did was lift all the dust and leave a large grey smudge. There had to be another way. So I went out and bought a can of hairspray. Holding the can above the print, I emptied the entire can into the air and let it fall down on to the print. It completely hardened the dust. Then I took a piece of card stock and slid it under the dust and lifted the most perfect footprint.” (I guess hairspray has other uses than making your hair feel like plastic.)
Det. Bailey finished his short power point. The rest of it was about fingerprints and lifting prints. The first place he will look for fingerprints in a stolen vehicle is the rearview mirror because that’s the first thing everyone does when driving a different car: they adjust the mirror. And, if someone breaks open a door, the first place he’ll check for prints is on the back side of the door because after someone breaks open a door, they’ll reach up and grab it, leaving a nice set of prints.
Having done a little of that when I attended the Citizen’s Police Academy several years back, I was already familiar with the process. But it was still interesting. Do you know what makes a fingerprint? If you look at your fingers, you’ll notice little ridges. In the valleys between each ridge, fatty acids and particles of dead skin cells gather. When you press your fingers onto a surface such as a window, door, table or even a golf ball, the acids and things in the valleys of your fingers remain on what you touched. So, you actually leave a “negative” of your print. To lift a print, they can use several things but Det. Bailey had us use either the volcanic powder (which is really volcanic ash pulverized into the finest particles you can imagine) or magnetic powder. First you take a picture of the print. “Sometimes we get a better image of the print from the picture than we do when we lift it.” Then you very lightly dust the print with powder. “Sometimes we use neon powder on a dark surface,” Det. Bailey told us, “but the fingerprint guys hate it!” Next, take a piece of clear tape, like packing tape, and put it on top of the print, gently smoothing it with a cork to get any air bubbles out. (If you use your fingers, you’ll leave your prints on it too.) Then carefully lift the tape, place it on a white card and write the case number, date, name of who lifted it, and where it was lifted on the back.
Did you know that though they have computers to search and match fingerprints, each match has to be checked by a real person? How would you like to spend ten hours a day staring at black and white lines to see if they match? No thanks!
Det. Bailey can lift fingerprints from all kinds of things. He even lifted one from a small feather once!
He showed us one other thing that can be used to lift fingerprints or any small impression. It’s pretty much a silicone substance that you mix together and then spread on a dusted fingerprint. That’s how he lifts prints from golf balls. “One time this stuff came in really handy,” he told us. “We were making surprise raids on junk yards looking for stolen cars. At one place we found a bobcat. We couldn’t find the serial number on that thing anywhere! So we had to call up a distributer to find out where in the world those things were. He told us they were under the front, up there, behind that, up this other place and then it would be there. We tried putting a camera up there, but it wouldn’t fit, the mirror didn’t work either and it would take about a week to get all the parts off enough to actually see the thing. That’s when I decided to try this stuff. I mixed it up, reached up there and spread it all over. After it dried, I peeled it off, put some ink on it and pressed it on a paper. We had the numbers. It was perfect. And yes, it had been stolen.”
|Two other class members and I fingerprinting|
|Dusting fingerprints and mixing silicone stuff|
Then it was hands on! We placed our fingerprints on things and then lifted them. Some of us even fingerprinted ourselves and checked them with the different kinds of fingerprints to see what they were: loops, arches, swirls, etc. We mixed the silicone substance and made prints of anything we could think of, including old credit cards, water bottle lids, knife handles and, of course, the golf ball. We tried the volcanic powder and the magnetic powder. It was about 8:30 when we decided we’d played enough and all found our seats again.
Detective Bailey told us that he really liked interrogating people. “I just like getting people to tell me their deepest darkest secrets,” he admitted with a smile. “I’ve been doing this so long that I can tell when someone is lying. No, I don’t go by all those things that they tell you are signs, like looking in a certain direction or folding their arms, because people are different. My kids all knew I could tell if they were lying and decided it was useless to try and tell me everything was fine in school if it wasn’t. One time I was working a case and had to interrogate this man. I figured it would take a while, so I called my wife to tell her I’d be working late. Well, all the interviews are videoed and played on a screen in another room. And, my wife and son, who was about 6, came in to bring me some supper. They walked into the room and the video was on of the interrogation. My son looks at the screen for a few minutes and then says, ‘That guy doesn’t have a chance.’ And sure enough, a few minutes later I had that guy bawling and confessing everything.”
|It was a hand print!|
|Can you tell what brand of shoe that is?|
|What about this one?|
We were dismissed and headed for home.
I hope you enjoyed this class and will be back again for our last class next week, as we take on the roll of a detective and work a crime scene! Until then, this is Rebekah.