Fingerprints: The Infallible Means of Identification

Imagine walking into a stranger’s house, ducking under yellow “CRIME SCENE” tape, to find blood-spattered walls and a corpse on the living room floor. The blood and small hairs found in the room belong solely to the victim. How are you going to find this murderer? By finding the unchangeable means of identification that every individual has: fingerprints. Detecting, collecting, and identifying the different characteristics of various fingerprints found at a crime scene can bring you one step closer to catching a criminal.

There are three kinds of fingerprints that can be found a crime scene. Visible prints, plastic prints, and latent prints. Visible prints come from a finger that was covered with some sort of colored material, such as paint or blood. Plastic prints are prints left on a soft material, such as wax or putty. Latent prints, also known as invisible prints, are caused by body perspiration or oils that were on the fingertip and transferred to a surface.

Locating prints at a crime scene can be both easy and difficult, depending on the kind of print it is. Visible and plastic prints are relatively easy to find, because the prints are visible to the eye. Latent prints are much harder to find, due to the fact that they are invisible. There are different techniques to detect these prints, and the technique used depends on the type of surface being examined.

For hard and nonabsorbent surfaces, powders will work to develop fingerprints. There are many fingerprint powders of various colors and composition. It is important that the color of the powder used contrasts with the color of the surface being dusted. Testing a similar area with different powders is one of the best ways to know which powder will work best. As far as brushes to use, camel-hair will work for most surfaces.

In their textbook, “Criminal Investigation,” Kӓren M. Hess and Christine Hess Orthmann give these four steps to dust for fingerprints:
1. Make sure the brush is clean. Roll the hands of the brush between your palms to separate the bristles.
2. Shake the powder can to loosen the powder. Apply the powder lightly to the print, following the contour lines of the ridges to bring out details.
3. Remove all excess powder.
4. Photograph.

Although every police department and crime lab has their own procedure, this provides a good outline for a proper way to dust for fingerprints.

Chemicals are generally used for prints on soft and porous surfaces. Three of the commonly used chemical methods are iodine, ninhydrin, and silver-nitrate (also known as Physical Developer). When using iodine, the object suspected of having fingerprints is placed in a cabinet with iodine crystals. The crystals are then heated, which produces a violet vapor that is absorbed by the oils in the fingerprints, thus revealing the print. Ninhydrin, available in spray cans or in a powder, will react with amino acids in sweat to reveal the fingerprint. This method, at room temperature, may take from as little to an hour to as long as twenty-four to forty-eight hours to develop prints depending on their strength. However, heat tends to speed up the development. The silver-nitrate method, also known as Physical Developer, turns sodium chloride in fingerprints to silver chloride. The material is briefly immersed in the solution and hung to dry. However, if combining these three chemicals, the order should be iodine, ninhydrin, and then the Physical Developer. The chemical reactions that take place in one test may destroy chemicals in the fingerprint used to react in another test.

After the fingerprints have been detected, they must be collected to examine in the lab, and later on during the case. Before any lifting or moving is done, photographs must be taken of all prints. Then, one of two procedures is followed. If the object with the fingerprint is small enough, it is to be covered with cellophane and transported back to the lab. If the object is too large or immovable, the print is lifted. The common way of lifting is to take wide adhesive tape, place it over the print, work out any bubbles, lift the tape, and place it onto a labeled card.

When it comes to the identification of fingerprints, there are three fundamental principles. The first fundamental principle says that fingerprints are individual characteristics. What this means is that no two people, and more specifically no two fingers, have identical fingerprints. There are many small details, known as ridge characteristics or minutiae, in every fingerprint. These exact characteristics will only match in fingerprints that came from that finger. This is what makes matches of fingerprints from crime scenes to those of suspects or victims important for solving crimes. Any fingerprint found will only match perfectly with the fingerprint of one individual.

The second principle says that fingerprints remain unchanged. Every individual is born with their fingerprints. Skin is made of layers of cells. Cells closest to the surface make up the epidermis, and beneath that layer is the dermis. It is the boundary of these two layers, known as the dermal papillae, that determines the fingerprint patterns. Therefore, once this area develops in a fetus, it will never change. According to Saferstein, many attempts to alter or destroy fingerprints have been made, including that of the “notorious gangster John Dillinger, who tried to destroy his own fingerprints by applying a corrosive acid to them.” It was later determined that his attempt failed.

The third principle of fingerprints says fingerprints can be classified based on general ridge patterns. The three classes are loops, whorls, and arches. Sixty to sixty-five percent of the population have loops, thirty to thirty-five percent have whorls, and about five percent have arches.

In general, a loop pattern has one or more ridge lines that enter and leave on the same side of the print. Loop patterns will usually have one core and one delta. The core is the center of the loop. A delta is a triangulation or dividing of ridge lines. There are two subdivisions of loops. Ulnar loops have loops that open towards the little finger, and radial loops have loops that open towards the thumb.

A whorl pattern usually has ridge lines that form a circular pattern. This fingerprint will have two or more deltas. Whorls are subdivided into four categories: plain, central pocket loop, double loop, and accidental. Plain whorls and central pocket loops are classified as such by having at least one ridge making a complete circle. A double loop has a combination of two loops and an accidental either combines patterns or does not fit into any category.

Arch patterns have ridge lines that enter on one side and leave on the other, while rising in the middle. This type of fingerprint has no core or delta. There are two subdivisions of arches: plain and tented. A plain arch rises smoothly in the middle, while a tented arch rises sharply.

Think back to the opening scenario. After detecting fingerprints and taking valuable lifts, you analyze and identify the general patterns and tiny details of the prints you’ve found. You take this information and compare it to the prints of all suspected murderers. You eliminate all possible killers to find the individual responsible. Of course! It’s the butler! It’s always the butler. Good detection, collection, and identification of fingerprints help to catch another criminal and solidify the usefulness of this infallible means of identification.

I can write about whatever I want? Cool! ROCKAPALOOZA!!!!

This past weekend I attended Rockapalooza at the Jackson County Fairgrounds. It was one of the best days I've had in a while. There were over 52 bands and they all rocked! They day was full of non-stop music and cool people. The crowds were't overwhelming and the local bands were all really friendly. They had tents set up to sell their merchandise and meet their fans.

A band from New York called As Summer Dies was there. I saw them a couple times last summer when they were in Michigan so of course I had to go see them again! It was nice to hang out with them, watch them perform, and catch up with them! The lead singer, Adam, kept having problems with their microphone during their set and you could tell he was getting frustrated. We talked to them after the show and he just kind of laughed it off.

They got a new drummer from the last time I saw them so I got to meet him at this show. He was really cool. He was friendly and kept talking to me. I even got a picture with him. I love all five of the people in the band, but the drummer, Mike, is definitely my new favorite.

Sevendust was the headliner and did an amazing job, as always. This was my third time seeing them. I even got to meet them before the show. The first 40 people in line at noon got to go in early and meet Sevendust and Otep. I got their autographs and everything. I met Sevendust once before but that was a few years ago. It was nice to meet them all again! Those guys are so friendly in person. Just wish I could have gotten a picture with them but no pictures were allowed.

Even though I got a little sun burnt and I'm still a little sore, I had an amazing day!

Social Issue

One social issue that I've always had a strong opinion about is the death penalty. I am completely for capital punishment. I feel that if somebody murders an innocent human being, they should be put to death. I know this is a controversial topic but I feel very strongly in the way that I do. A lot of people think it's wrong to kill someone as punishment for killing. However, it only seems fair that the punishment matches the crime. Also, if you want to take the religious side of it, the Bible even says "an eye for an eye" and "a life for a life" (I can't remember exactly where but you can easily look it up). So, if you want to say it goes against Christianity, the Bible can be interpreted as saying that those who kill should be killed. Another argument people make is that innocent people can be killed, but that is another problem entirely. That is a problem with the court system and the way the cases are handled in court. That is a problem with the process of convicting a suspect. That has nothing to do with whether murderers should be killed.

Think of it this way: If your mother, father, son, daughter, brother, sister, boyfriend, girlfriend, husband, wife, or any other family member or close friend was murdered, would you not want redemption? Revenge?

Oil Spill

I think what is happening in the Gulf of Mexico is absolutely terrible. Corporations don't seem to think about the environment when they're trying to make money. This is something that is going to be affecting us for years down the road. Animals are going to be affected. The wildlife, the agriculture, the lifestyles of people living in the Louisiana, will all be affected. It's quite a tragedy that the environment seems to be so unimportant to big corporations.

Boycotting BP sounds like a good idea, but unless a large amount of people do it, the affect won't be noticed by the company. If a large group of people can agree to boycott the company, it might make them see how harmful what they've done is. Unfortunately, I don't think enough people will participate in a boycott. Punishments should be dealt out, but it seems the environment is losing its importance every day.