Crimes are inevitable as long as society exists. The process of detecting and investigating offenses has evolved, given the advancements in science and technology. The methods of crime investigations have transformed mainly due to the progress of forensic science. Forensic science is an essential section of the justice system that helps authorities determine how an offense was committed. It can also help the authorities determine when the offense was committed. This technology can also help to identify the perpetrators of the crime. Additionally, forensic science can help authorities assess physical evidence and feel confident while deciding a criminal case.
Forensic Science Explained
The term forensic refers to matters associated with the court of law. Forensic science is the application of science to issues related to the law. It involves connecting crimes, places, and individuals involved in criminal activities. Forensic science is handy in detecting offenses, establishing guilt, and solving criminal cases. This technology enables professionals to learn a drug's composition and match DNA to people. It also helps experts to examine blood spatter patterns, among other issues. The outcome of forensic science is always crucial evidence in courts of law.
How Forensic Science Can Be Used To Solve Crimes
Prosecutors and criminal defense attorneys depend on forensic science to approve or disapprove of the evidence they present. For example, if there are no witnesses, the prosecutor could use the evidence gathered from the crime scene to obtain DNA evidence. The DNA evidence will help identify the suspect linked to the crime. Forensic science could even assist investigators in establishing when the offense was committed, including the actual date and hour.
In a murder crime, forensic science could help identify the possible suspect and the victim. The investigators could identify the deceased by analyzing the skeletal structure or dental work. Forensic science could also help determine or narrow down whose body it is. For example, a 25-year-old young man is 130 pounds in weight and five feet tall.
Forensic science technology can also help determine what killed a victim, giving the authorities a clue on the weapon used in the murder. This could lay the foundation for searching for the murder weapon and suspect. For example, law enforcement officers could establish that a .45-caliber handgun was used to kill the victim. The law enforcement could then confirm from the database whether a person owns a registered .45 firearm in the region.
The Application Of Forensic Science In Investigating Crimes
The following are the typical applications of forensic science in investigating offenses:
Forensic Pathology
Forensic pathology is the procedure that involves examining a dead body to ascertain the cause of death. This usually takes place during an autopsy. A pathologist performs an autopsy in a hospital in the pathology department. In the case of a confirmed homicide or a suspicious death, law enforcement is always present during the autopsy. The presence of law enforcement usually helps them to gather evidence.
A pathologist cuts open the body while performing an autopsy and carefully examines, analyzes, and documents the body parts to ascertain what killed the victim. Pathologists also consider the common after-death indicators or post-mortem to estimate the time of death. The indicators could include the following:
- The progress of decomposition.
- The degree of rigor mortis.
- Post-mortem lividity.
- The temperature.
A pathologist is also trained to determine what killed the victim. The following are the common causes of death:
- Depriving necessities of life, mainly food.
- Laceration or stabbing.
- Blunt force trauma.
- Toxic substances.
- Electrocution.
- Asphyxiation, and
- Shooting.
Blood Spatter Analysis
Blood spatter analysis, also known as blood pattern analysis, is a relatively novel forensic specialty. It is important in a crime situation where blood marks are present. This technology involves determining how blood is distributed at the scene of crime. Whenever a victim sheds blood during an attack, specific distribution patterns are common.
This analysis is crucial in crime reconstruction. This technology reveals how the perpetrator struck the victim and the direction of the attack. For example, the victim’s blood will be distributed in a droplet spatter behind the victim if the perpetrator uses a bat to strike the victim.
Hair and Fiber Analysis
It is unlikely to be at the crime scene and fail to carry something with you or leave something behind. The exhibits of hairs and fiber are ideally explained using this theory. People constantly shed various materials from their clothing or bodies. In this case, a perpetrator of a crime could leave behind strands of hair from their head. The perpetrator could also leave fibers of their clothing material and fingerprints on the items he/she touches.
The perpetrator could also carry fiber from the victim's clothing or hair when leaving the crime scene. Analysis of hair or fiber offers corroborative evidence. Investigators use this technology to establish the similarities between the suspect's hair and the one collected at the crime scene. Investigators can carry out DNA analysis if the hair sample has root tissue.
Ballistic Analysis
Given the prevalence of gun-related offenses, most investigators understand ballistic analysis. Ballistics studies items launched into flight and how they are launched and flown. Investigators study various forms of firearms, including long rifles, shotguns, and handguns.
Authorities always employ different techniques in ballistic science to deal with the unique aspects of firearms and bullets. The function of ballistic comparisons is to ascertain if a particular firearm was used to shoot an unknown cartridge or bullet casing. Sometimes, this investigation is referred to as ballistic fingerprinting. The analogy attached to ballistic comparisons is that if a particular firearm touched a bullet or cartridge casing, it would leave some recognizable marks known as ballistic fingerprints.
Firearms are categorized by their chambering, ejector mechanisms, caliber, and firing pin for ballistic purposes. Ballistic analysis help law enforcement eliminate suspect weapons at level one. For example, if law enforcement finds a .38 caliber bullet at the scene of the crime, then the bullet could not have been shot from a .22 rifle. Investigators often make more decisive comparisons at level two examination using ejector markings, striations matching firing-pin comparison, and chamber markings.
Trajectory Analysis
In addition to a ballistic fingerprinting examination, trajectory analysis is another common form of ballistic science. A trajectory is a path a bullet travels from when it leaves the gun barrel to the time it loses propulsion energy and comes to rest, particularly after hitting the target. The bullet’s flight could be short, whereby the suspect shoots the victim at close range, or long, whereby the victim is one mile or more from the suspect.
When a bullet travels a longer distance, it travels on a path or in an arched trajectory. Upon reaching its destination, the bullet will have a unique entry angle into the target. Investigators can determine where the bullet came from by considering the trajectory and the angle of entry. The trajectory of the bullet will also help the investigators know where the shooter was standing. This is crucial when a bullet travels through different objects, like the walls, before hitting the victim. Studying the trajectory of the bullet will show whether the shooter was moving in a drive-by shooting case. The trajectory would also show the direction of travel if the shooter was moving.
Fingerprint Matching
The forensic science of fingerprints has a long history in criminal investigations because fingerprints are unique to a person. If an expert conducts an investigation, the courts accept positive fingerprint matches as proof of identity. Fingerprints and dental X-rays were the only reliable means of objective identification before biometric scanning technologies and DNA analysis.
Fingerprints are unique ridges and line patterns on the plantar surface of a person's hands and fingertips. Since the 1800s, these unique patterns have been grouped into classes and features, enabling an individual's fingerprints to be cataloged in a searchable system or database.
The impression of a person's fingerprints always remains on the surfaces of items that he/she touches. A person's body produces oil, which acts like invisible ink that adheres to the smooth surfaces that he/she touches. When a colored fingerprint powder is applied to the surfaces you touch, the invisible fingerprints will be visible. The colored fingerprint powder sticks to the oil, showing images of lines and ridges that form a fingerprint.
Your fingerprints could appear on dry paint, plastic, and paper surfaces. Sometimes, a suspect's fingerprints are visible when he/she touches a surface, and his/her finger has foreign material like blood or ink. Additionally, if you put your hand on a malleable surface like clay or cheese, investigators could rely on molded impressions of the fingerprint.
Physical Matching
This technology could range from matching the torn edges of a piece of wadding paper to the original paper from which the piece was torn. Investigators could also gather the information, which the court would accept as expert evidence, using sophisticated aspects of physical planning. For example, while investigating a crime, law enforcement officers or other experts can perform physical matching using the following items:
- Broken glass.
- Plastic fragments.
- Tire prints.
- Glove prints.
- Tool impressions.
- Fingerprints, and
- Shoe prints.
The investigators could carry out the following examinations:
- Accidental characteristics.
- Class Characteristics.
Accidental characteristics are unique marks and features that develop on an item because of wear and tear. The process of physical matching calls for higher levels of expertise with items like broken glass and plastic fragments. Some comparisons even require microscopic examination and photographic overlay comparisons.
Class characteristics involve glove prints, tool impressions, shoe prints, and tire prints. The authorities can sort and classify these items during an investigation based on their type, pattern, model, and size. If shoe prints belong to a certain class, investigators will concentrate on individuals with shoes within that class description.
Deoxyribonucleic Acid (DNA)
DNA plays a vital role in forensic science. It assists the authorities in exonerating the innocent and convicting the guilty. Law enforcement relies on genetic material in DNA to identify suspects. They do so by analyzing the biological evidence present at the crime scene. The biological materials could be vaginal swabs, blood, saliva, semen, and buccal swabs. In most cases, these materials are deposited in small quantities on various surfaces at the crime scene without the suspect's knowledge.
The investigators could identify the suspect by processing the DNA from biological materials and performing a DNA statistical interpretation. Today, most private and public laboratories conduct thousands of DNA tests in California alone. They also have extensive computer databases containing DNA profiles from biological samples secured from:
- Individuals arrested for crimes.
- Convicted individuals.
- Scenes of crimes.
As a result, law enforcement officers have been able to solve crimes using DNA analysis. Forensic DNA testing helps to hold the guilty accountable for their offense. It also helps to exonerate the innocent from offenses they did not commit. Many people ended up in jail before DNA analysis. This happened after wrongful convictions because of faulty evidence and witnesses.
Geographic Profiling
Geographic profiling is a strategy for enhancing investigations into serial violent crimes. The technique examines areas associated with offenses to determine the most likely place where the perpetrator lives.
Criminal Profiling
Criminal profiling entails concluding criminals' physical, behavioral, emotional, psychological, and vocational traits. However, there are other approaches to criminal profiling, each with varying degrees of correctness regarding underlying theory, insight, and logic.
Forensic Odontology
In the context of criminal justice, the handling, inspection, and assessment of dental evidence is the practice of forensic dentistry. It is sometimes known as forensic odontology. The application of forensic dentistry extends to civil and criminal law.
Forensic Document Analysis
Questioned Document Examination, abbreviated as QDE in forensic science, is the analysis of documents that might be contested in court. Its main goal is to use scientific procedures and methods to offer proof regarding a dubious or suspicious document.
Other Forensic Sciences
The following are other forms of forensic sciences used in the investigation of crimes:
- Forensic identification sections.
- Crime detection laboratories.
- Forensic data analysis.
- Forensic engineering.
- Forensic archeology.
- Forensic entomology.
- Chemical analysis.
Crimes That Forensic Science Can Solve
DNA evidence has become a popular part of investigating and charging all offenses. Apart from murder, drug, and sex-related crimes, some additional offenses can also be solved with forensic science.
Drug Crimes
In drug crimes, forensic science comes in handy to determine the chemical makeup of a drug. This technology assists the law enforcement to determine if a suspect possessed unlawful drugs. If the forensic test results were positive, the prosecutor would use the outcome to accuse the perpetrator of possessing a controlled substance.
Death By Poisoning
In case of death by poisoning, forensic science can also be used to determine the drug which killed the victim. This technology could also assist law enforcement in narrowing down on the suspect who accessed the drug used to kill the victim.
Sexual Violence
DNA evidence can make or break the outcome when law enforcement investigates a case of sexual violence. It is always a crucial tool in achieving justice for victims of sexual assault. DNA is the material in a person's cell that determines characteristics like skin color, hair, and eyes. People have different DNA, except for identical twins.
Investigators can use DNA to identify suspects accurately, similar to how fingerprints are used. DNA evidence can be collected from semen, skin tissue, urine, sweat, saliva, and blood. The law enforcement officers advise victims to avoid urinating, cleaning fingernails, or bathing until after a sexual assault forensic exam has been conducted. A Sexual Assault Nurse Examiner (SANE) could conduct the examination. Any other trained medical expert can also perform a DNA test.
Once the DNA is collected, it will be presented to law enforcement, who will take it to the crime laboratory. The lab technician will analyze the material and create DNA profiles that are unique to a particular person. The lab technician works with the police officers to compare the profiles to the DNA of the potential perpetrators. If the suspect is unknown, they could compare the DNA profile against an extensive database known as CODIS. The meaning of CODIS is the Combined DNA Index System. The FBI runs CODIS. Law enforcement can use CODIS to identify a suspect that the victim does not know or is not familiar with.
Find a Criminal Defense Attorney Near Me
When you commit an offense, law enforcement officers can use many methods to investigate the crime and determine if you are the perpetrator. One of the most reliable ways of gathering evidence is through forensic science. Forensic science can include Blood spatter analysis, hair and fiber analysis, DNA testing, geographical profiling, trajectory analysis, etc. If you learn that you are under investigation for an offense, you should contact an experienced attorney immediately.
The Los Angeles Criminal Defense Attorney is a premier law firm with experienced attorneys who understand contemporary evidence gathering. Our attorneys understand forensic science and its role in crime investigations. We will help you create a convincing defense, irrespective of the evidence the prosecutor presents against you. Contact us at 310-564-2605 to speak to one of our attorneys.
