Everyone is extraordinary, unique like no other. This may look like a nice compliment at first, but in a certain context, it is a simple fact and furthermore, something that shows us the true identities of criminals in the case of a crime comitted. And as unique as everyone is, knowing that is never the same as showing it.
When detectives and crime scene investigators try to identify a criminal or a victim, they have to find the clues that make every individual different from each other; there are multiple different signs that are distinct in every human being -save for identical twins- and one of the most precise ones is DNA analysis.
DNA analysis is an overall look on the whole of a person’s biologic build, and is nearly fool-proof, albeit time-consuming and expensive. Thus, there has to be other reliable ways to find a potential criminal/victim’s identity.
The large-scale effects of DNA analysis could actually be hard to believe in some cases. One of the said cases is the time when a man was blamed for burglarizing a property and the police took some saliva samples from the scene. The man had never been convicted of a crime before, yet when the DNA test results came in, they found out that the DNA matched another sample taken from an unsolved and vicious murder’s scene years ago. After that, during his interrogation, the man pleaded guilty and was imprisoned. Here, DNA analysis played a pivotal role in connecting seemingly disparate events, showcasing its potency in solving complex criminal puzzles.
Blood, often a silent witness at crime scenes, has also played a crucial role in forensic investigations since blood as we know it is a tried way of learning about who someone is or who they were during their lives, whether the blood itself is still coursing through your veins or if it’s splattered against surfaces. Since the early twentieth century, we’ve known that there are different blood types, courtesy of scientist Karl Landsteiner, and it was started to be used as a way to identify potential murderers. It helped with the investigations for a while, but proved to be useful only to a certain decree, siince everyone is one of the four blood types (A, B, AB, 0) and out of ten people, four are the A and five are the 0 type, it could only get us so far in finding criminals. But with the discovery of modern DNA tests, with only one in 40 millionth of a blood drop, we can strike the suspect as guilty or innocent. For the serologists -the scientists who examine bodily fluids in in forensic investigations- to actually study the blood in a scene, the blood sample is carefully taken to the lab and usually mixed with some saline to be liquified again.
In some cases, blood is hard to be told apart from other liquids and it could easily mix and be mixed with a variety of different things, so crime scene investigators may need to use blood probability tests. Detectives use luminol and floresin sprays to see wether or not a seemingly random stain on a carpet or a spot on an otherwise clean clothing is blood. There is also Hemastix, which is the easiest test to be put to used, applied with small sticks with test chemicals on the tip. The scene investigators wet the stick and rub against the stain to see if it turns from yellow to green to indicate that the stain is blood.
Bones and teeth, resilient remnants in the aftermath of a crime, serve as silent narrators in forensic anthropology. After a body is burnt over by flames and eaten away by animals, all that’s left of a corpse are bones and a skull. Usually, it takes just around a month for all of the meat, organs, tissue and muscles of a human body to be fully devoured by insects and bacteria outdoors, the process is even faster by fire or the use of strong bases and acids; and while a skeleton may look like something from a horror movie set, to crime scene investigators, it’s basically an open book that tells them a lot of things about the person whom the bones beloned to.
It’s forensic anthropologists’ duty to find out who was burned or buried, and by using the bones and teeth, they can determine the victim’s age, sex, height, and race. Forensic odontologists can even give the skulls a name after comparing dental records. To determine the age of a skeleton, forensic scientists look at the development and decay of bones and teeth. Teeth usually start coming in by 6 months, and the process keeps going until the person’s 13; the same is true with bones, which are soft and separate and get harder and connect together with age, eventually giving up and sharpening once the person starts reaching their old age. To determine gender, scientists usually look at the pelvic bones; a female’s pelvic bones are prominently wider and visibly rounder than a male’s. An anthropologist can also understand the strength of a person, whether or not they were trained in any way. Looking at the points where their bones are linked with the muscles and pronounced abrasion could give them ideas about the job they might have had. Some injuries and illnesses can leave permanent marks on the skeletal remains too.
The pursuit of criminals often involves a methodical journey of elimination and profiling: when a crime is committed and there is no obvious criminal, detectives start eliminating possible suspects and find more of them along the way. Through eliminating the suspects that aren’t likely to have committed the crime, they narrow the pool of culprits down to a few people. And if that fails, then they go with criminal profiling which is based on analyzing the way the crime was committed and matching it with previous cases of similar actions of a criminal. In a police station, the police mark each place a criminal made an appearance in on a map to keep track of their movements and to anticipate the next place they could go and mapping a criminal’s movements, scrutinizing phone records, and studying security camera footage has become indispensable tools in the relentless seek of bringing criminals to justice.
If there’s not much information about a criminal and vague profiling from eyewitnesses, police can still narrow down a lot of the general suspects list. If we know that the criminal is a young male who ran away from the crime scene and then drove a car to get away faster, then we can easily eliminate every female suspect, everyone who isn’t between the ages of 16 and 40, people who aren’t fit enough to be able to run away from the scene, and everyone who can’t drive a car. And even with a vague idea about our suspect, we can significantly lessen the number of possible criminals.
But how do you prove evidence for a crime? It is known that no matter how sure of themselves, witnesses can confuse suspects with actual criminals and have a hard time actually choosing them from between photos of suspects. The unclear security camera footage and lie detectors remain equally untrustworthy. We would all trust our memories, especially in a situation like being witnesses to a crime, but it might not be as easy as it may seem to be to be able to identify someone we briefly saw weeks ago. A witness may be told to identify and choose the criminal in a room of suspects or from photos of criminals with past charges, but while some give correct answers, the wrong answers could put the person they “identify” into the unjust position of being a suspect. Close-circuit security cameras are also used to identify the criminals, the before or after of the crime, or at the very least information about the way the crime was committed.
In summation, in the intricate dance of crime and justice, the arsenal of forensic techniques, from DNA analysis to bone examination, provides investigators with a symphony of clues. Each method is a brushstroke on the canvas of crime-solving, bringing clarity to the shadows and unraveling the unique tales embedded in every individual’s existence.
