Forensic Science to Solve Crimes

A mysterious white powder, a blood smear, and a moldy ham sandwich—completely unrelated items to most. But they could be meaningful for forensic scientist, who analyze physical evidence and samples for clues to solve crimes. Television shows such as Bones, CSI, and Law & Order have glamorized forensic scientists and made the field more popular, so competition can be intense. However, if you have a strong desire to shape the world of justice by using science to solve crime puzzles, then a career in forensic science could be worth pursuing.

Forensic science is the application of a broad spectrum of sciences and technologies to investigate and establish facts of interest in relation to criminal or civil law. To become one, one must have, at minimum, a bachelor’s degree in science. Common majors include chemistry, physics, biology, or forensic science. About 90% of forensic chemists work in labs associated with a federal, state, or local police department, medical examiner’s office, forensic services lab, or branch of the Federal Bureau of Investigation (FBI). There are a few private labs that carry out forensic analyses. They tend to have rigorous work hours, but if you are very interested in the field, this shouldn’t be a problem for you.

When it comes to chemistry, this field of work relates to forensics in many ways. For example, blood analysis. Aside from being used for identification of suspects, the contents of blood on a crime scene can be evaluated to reveal the presence of substances. For this evaluation, a chemist will perform a chromatography test, which uses intense heat to separate the blood into different contents. Afterward, a chemist determines the level of substances such as alcohol or medication that would affect the suspect’s actions and motivation during the given crime.

Another practice that forensic scientists do that relates to chemistry would be DNA forensics in criminal cases. DNA forensic is used in criminal cases to match the DNA of an individual to that of a body cells left at a crime scene, such as skin cells, hair, and blood. The FBI most commonly uses STR- analysis for its cases. With STR- analysis, chemists take DNA samples from areas at the crime scene. These are then compared with the DNA profiles of individuals in an expansive database called CODIS to identify suspects.

The third and final topic that forensic scientist touch on is firearms analysis. Chemistry is often used in crimes involving firearms in order to identify information from recovered bullets and residue. For example, a forensic scientist will examine a suspect’s hands and clothes with infrared lights to look for gunpowder residue. If this residue matches that of the bullet found in the victim, there is evidence that the suspect recently fired the same type of firearm responsible for harming the victim. If no gunpowder residue is found on a suspect, a chemical analysis of the bullet can still reveal information such as the type of firearm used and how long ago the bullet was fired.

There are several popular criminal cases where these chemistry based practices were applied. Forensic scientists are even sometimes the reason cold cases get solved. For example, the infamous O.J Simpson case. As most of us know, Nicole Brown Simpson and her friend Ronald Goldman were fatally stabbed on the evening of June 12th, 1994. Although 99% of the world believes OJ Simpson is guilty of murdering his ex-wife and her friend, one question surrounding the case remains a complete mystery: did two police plant DNA evidence at the scene to try and create a slam-dunk case? Detective Furman, who was outed as a violent racist during the trials, was accused of planting OJ’s glove at the scene. Additionally it was proven that Simpson’s blood sample was brought to the crime scene by a police evidence technician, and it was later discovered that the tube of blood at the crime scene only contained 6cc of blood when 8cc had been extracted. Simpson’s blood at the crime scene reflected DNA that had been mixed with EDTA, a substance added to blood taken for DNA testing. Furman pleaded no contest to charges against his person regarding this OJ “conspiracy” and is now a convicted felon. If it wasn’t for the work of forensic scientists and the application of chemistry, this scheme wouldn’t have been put to rest.

Another case would be the murder of Anna Palmer. It was DNA evidence that led to a conviction in the 1998 murder case of 10-year-old Anna Palmer who was attacked and killed outside of her own front door in Salt Lake City. The crime was evil, and included multiple stab wounds to her body, but following the crime, investigators had no witnesses, little evidence, and no apparent suspects, the news station reports. However, in 2009, forensic analysts were called in to assist in the case, and they decided to examine the girl’s fingernails for DNA samples. Using visible and alternative light sources to look for DNA not belonging to the girl, they made a hit, and matched it to a man named Matthew Brock, who had lived a block away at the time of the her murder and was age 19 then. Brock was already in prison serving a 10-year sentence for a sex-related crime with a child, and he pled guilty in 2011 to an aggravated murder charge in the death of Anna Palmer and is now in prison for life.

Finally, the murder of Leanne Tiernan was a case solved by forensic scientists and their knowledge in the field of chemistry. In August 2001, a man walking his dog in Lindley Woods in West Yorkshire, found the body of 16-year old Leanne Tiernan buried in a shallow grave. Her head was wrapped in a black plastic bag, held in place with a leather dog collar; zip ties were also holding her wrists together. Her body was wrapped in green plastic trash can liners and tied with twine. She was found about ten miles from her home in Leeds. She had been walking home from a Christmas shopping trip with her best friend in November 2000, when she disappeared. However, pathologists said her body had not been there since November. She had been strangled and her body was stored at low temperatures in the intervening time.

Police were able to track down the suppliers of the dog collar and found a man who had bought several dog collars similar to the one found around Leanne’s neck. This man was John Taylor, a poacher who often hunted in the same woods where Leanne’s body had been found. The twine she was wrapped in was an unusual kind, used for rabbit netting, and was tracked down to a supplier in Devon, which had only produced one batch. It matched twine found in John Taylor’s home. Some of the cable ties used on Leanne Tiernan were of a type used almost exclusively by the patent company of John Taylor’s employer, Parcel Force. When the police searched John Taylor’s house they found more of the cable ties and one of the dog collars.When the forensic team examined Leanne’s body further, they also found several strands of dog hair. The hair was sent to scientists in Texas who produced a partial dog DNA profile. However, it turned out the dog he’d owned when Leanne disappeared had already died. Even though it never led to a conviction, this was the first time that dog DNA was used as forensic evidence in a British criminal case.

The chemistry behind forensic science is one of the main reasons criminal cases get solved on the daily. If it wasn’t for the chemistry based practices used in the forensics field, forensic scientists would not have the material needed to complete the tasks that this occupation has laid out for them. I chose this topic to write about personally because I’m very interested in this field and I am considering pursuing this in college. It is a rigorous and somewhat stressful career, but I believe I could take on the challenge.