The field of crime scene investigation is constantly changing. With advances in technology and science, we have more tools than ever to help us solve crimes. But in order to take advantage of these tools, a crime scene officer needs to stay up-to-date with the latest developments and understand the capabilities of specialists in the field. Your goal is not to acquire the same level of knowledge as the expert, but to have enough knowledge of the field to recognize what the expert can accomplish with the right evidence. With this knowledge, you can tackle your crime scene in a systematic and thorough manner and provide the experts the evidence they need. In this issue, I’ll give you an overview of some key areas you should focus on when processing a scene.
To begin with, advances in fingerprint technology now allow experts to lift prints from surfaces that couldn’t be processed in the past. Gathering as much fingerprint evidence as possible is always important, so you should still begin by processing surfaces such as vehicles and windows right at the scene. But you should then look for other potential sources of prints. For example, experts can lift latent prints from documents, papers, and adhesive tape. If these items are present, carefully collect them and send them off to be processed by your local or state lab.
DNA, of course, has become a crucial part of crime scene investigation. So much can be done with DNA, but if you don’t have knowledge of what the experts can do, you may miss the opportunity to identify a suspect. Besides looking for hair, blood, and cigarette butt evidence, you should also look for any material the suspect may have come into contact with. Take the time to swab surfaces such as the steering wheel of a vehicle or the grip of a gun. Also remember that if you are fingerprinting and develop smudges with no ridge detail, the smudges can be swabbed for DNA testing. In the past, we couldn’t get DNA from these sources, but now we can. In addition, you should also know that DNA can be retrieved from things like knit caps, baseball caps, and eye glasses. Collect all of these items for the DNA experts and you’ll increase your chances of success.
A good example of a crime scene that requires specialized knowledge is one involving a decomposed body. While a decomposing body presents many challenges, you can gain vital information if you know what evidence to collect and the right expert to contact. You can actually purchase an entomology kit that allows you to process the body right at the scene. By following the directions that come with the kit, you can collect the maggots and other samples from the body. Once you have the necessary samples, you can send them to an entomologist. Through an analysis of the samples, the entomologist can determine how long the body has been at the scene.
Another important type of evidence is blood spatter. A lot of information about homicides or other crimes can be gained by studying the pattern of blood on a surface. Your first step should be to document the evidence with photography and diagrams. Then, depending on the complexity of the evidence, you may also need to bring a blood spatter expert to the scene. Again, your goal is not to acquire the same level of knowledge as the expert, but to have enough knowledge of the field to recognize what the expert can accomplish with the right evidence.