Forensic Science and CSI
Forensic Science, in its most basic definition, is the application of science to law. It is an umbrella term used to describe professionals from a wide range of disciplines that use their expertise to aid members of the legal system in their investigations. The general public is familiar with the importance of DNA evidence, blood pattern analysis, and other well publicized disciplines that can benefit crime scene investigations. However, depending on the crime, there is a wide variety of fields that are often overlooked by the media that may be applicable to a case. The primary issue between the forensic fields and the media is that all of these fields are poorly represented on crime scene television shows.
Members of the forensic science community can appreciate how television shows like Dexter have publicized the use of science in civil and criminal investigations. Unfortunately, these shows simplify complex scientific procedures to meet allotted airtimes, giving the general public unrealistic expectations of forensic science. Procedures that take days, weeks, months, or years in the real world are completed within 45 minutes on television. Worse still, the science in these shows is more often than not inaccurate and improper techniques are used. Crime scene dramas have even been used in forensic science university classrooms as a learning opportunity for students to point out everything that the characters did wrong. On these shows, good quality evidence is always found and linked to the perpetrator, and the case is always solved. While this makes for a good television show with a climax and a well-rounded conclusion, it is nowhere near realistic. The popularity of these fictional crime scene shows has led the public to believe that usable forensic evidence will be found at every crime scene and that every case should be supported with forensic evidence. These false ideas originating from fictional television shows are known as the CSI effect. The repercussions from these television shows influence on the general public are seen every day in real legal proceedings.
Crime Scene dramas remain popular and many are very entertaining, however the best thing we can do for our legal system is to fight the CSI effect with education. The general public needs to question EVERYTHING and never take anything portrayed on fictional crime scene shows as truth. By reading this article you are already taking the first step and scratching the surface on the many differences between real and dramatized crime scene investigations. Below, you will find real world examples explaining what it really means to be a crime scene investigator and a forensic scientist.
The Real CSI Wardrobe
Thanks to shows like CSI: Crime Scene Investigation, Law & Order, and Bones the general public has seen actors stroll onto the scene of a homicide wearing high heeled shoes with their hair blowing in the wind. On TV, it seems that so long as the investigators are wearing gloves, they are deemed safe and professional. In reality, crime scene investigators, both on-scene and in the laboratory, have to wear a lot more protection known as Personal Protective Equipment or PPE. This protective equipment creates a barrier between evidence and personnel and is therefore crucial in ensuring two very important points. First, that the crime scene and evidence does not become contaminated by the on-scene and laboratory investigators and second, it ensures the safety of investigators by preventing direct contact with potentially hazardous materials like blood borne pathogens, drugs or harmful chemicals. While not as glamorous as portrayed on television, crime scene investigators, like police officers, and lab personnel, like TheDNALab employees, can be found wearing very important equipment shown below.
Mask: protects personnel from breathing in harmful debris. Prevents the contamination of evidence by providing a barrier to stop coughing, sneezing, breathing and talking over evidence.
Hair tied back and/or covered: stops personnel from having their hair caught in equipment used on the job. Prevents the hair from contaminating evidence.
Jump suit: used on scene, covers the entire body and clothes to prevent contact with harmful substances and to create a barrier that prevents skin cells and hair from contaminating evidence.
Lab coat and long pants: accomplishes the same purpose as a jump suit in a laboratory.
Gloves: covers the hands and wrist areas to prevent contact with harmful substances and to prevent skin cells from contaminating evidence.
Closed-toe flat shoes: Protects feet from hazardous material found in the lab or the evidence itself. Limits the risk of trips and falls.
Shoe Covers: Put on right before entering a scene, they provide an extra layer between personnel and the crime scene, preventing shoes from becoming imbedded with potential evidence, or carrying contaminants on scene.
Arming Yourself against Hollywood “Science”
On television, the same three or four members of the CSI team are seen collecting evidence, processing it in the lab, conducting interrogations, and testifying in court. In reality, these tasks are usually divided among several different groups of professionals. The TV CSI team also violates many, if not all, of the cardinal rules that real investigators follow. To fully understand what is poorly portrayed in Hollywood, you first need to know what is considered to be best practices on scene and in the laboratory. Having an idea of what should be done during an investigation will help you call out what TV shows are doing wrong.
CSI – The Basics from TheDNALAB
Crime scene investigations involve several steps and extensive work. Here, we will briefly touch on some of the key responsibilities of CSI members once the scene has already been secured. An extremely important step that is always glossed over on television is the importance of documenting the crime scene. This does not simply mean taking a few pictures of the evidence. Officers keep detailed notes that include important information like a description of the scene, where each item of evidence is located, who enters and exits the scene and when, statements from victims and witnesses and much more. A sketch of the crime scene is also done to show where each piece of evidence is located in relation to each other. Photos of the overall scene, close ups of evidence next to a scale will all be taken. Entire books can be found dedicated to the various techniques that crime scene photographers utilize in order to capture as much detail as possible.
Despite television characters walking around a crime scene in a seemingly random order, real life investigators select a specific search pattern to ensure the scene is thoroughly searched. While searching for evidence, what investigators are looking for will depend on the context of the crime. The numbering and collection of evidence is no simple matter. Extreme care is taken to prevent the contamination of evidence by wearing the proper PPE and with the techniques used to collect and package each item separately. For example, a t-shirt found at a crime scene that has a wet red stain on it (potentially blood) will not simply be placed in a plastic bag or placed in the same bag as another piece of evidence. After proper documentation, the t-shirt will be left to air dry as much as possible and will be placed in its own, labelled, paper bag. Placing biological material like blood inside a plastic bag creates a breeding ground for mold and bacteria therefore risking the quality of the evidence. Clearly, a lot of work and consideration goes into a proper crime scene investigation.
Forensic Laboratory – Behind the Scenes
A forensic laboratory may only specialize in processing very specific types of evidence. TheDNALab focuses on DNA evidence, where Canadian police forces send boxes of crime scene evidence that are then processed within our laboratory to attempt to obtain DNA profiles. Within our DNA laboratory there is an abundance of preventative measures and procedures set in place to ensure no contamination takes place and to obtain accurate results. The root of a good laboratory is one that is set up properly, organized, and adheres to strict work instructions.
Laboratory Setup and Workflow
TheDNALab is divided into two main sections. The first area, known as the item examination area, is where technicians remove a single article of evidence from its storage container at a time and test for biological material like blood or saliva. Certain pieces of evidence, like bones and teeth, are examined in a separate ventilated biohazard room if they pose a higher risk to exposing staff to biohazards and to further limit the risk of cross contamination between items. Once the technicians have completed their tests and have located biological material or possible biological material, they take a small sample, place it in a labelled test tube, and give it to technicians in the second section of the lab. The second section of the lab is further divided into several rooms, each designated for a specific step of the process required to obtain a DNA profile. There are also separate work areas and equipment for samples from a known source, versed crime scene samples or unknown sources. TheDNALab has a one-way workflow, meaning there is only one entrance and one separate exit in the laboratory. Personnel can only go forward, once they move from the first room to the second room, they cannot backtrack to the first room. Instead they must continue and exit the lab at the appropriate exit point. The reasoning behind this laboratory setup and workflow is to avoid contamination between the lab personnel and evidence and between different items of evidence.
When working in a laboratory, technicians adhere to work instructions, commonly referred to as Standard Operating Procedures (SOPs), which have been set in place after extensive testing (validation). Each procedure is thoroughly tested prior to being used with casework samples to ensure that high quality results will be obtained. Technicians also reduce the risk of contamination through practices including limited talking, always wearing the appropriate PPE, and meticulous laboratory cleaning schedules. The importance of cleaning cannot be stressed enough. In the item examination area, personnel sterilize their workspace and change their gloves between every piece of evidence to avoid contamination between crime scene artifacts. Disposable lab equipment is also used wherever possible, with a new one used for each evidence sample. Finally, to remain organized, technicians maintain both hard copies and electronic copies of each procedure they carry out in the lab. This allows staff to track what exactly was done to every piece of evidence and when.
Note: This article was written with the help of Richard Saferstein’s Forensic Science – From the Crime Scene to the Crime Lab second edition textbook. Further detail on the topics presented above and more can be found in this book.