How Forensic Evidence is Presented to a Jury

Forensic Evidence is The Eyewitness

Author: Jack Claridge - Updated: 20 July 2010 www.ExploreForensics.co.uk/

There are many different ways in which evidence can be presented to a jury in order for them to fully understand the nature of what they are being told or shown.

These methods may include the use of visual aids, video footage, still photographs, catalogued pieces of evidence (referred to as exhibits), audio recordings, transcripts of conversations that have taken place and also maps and handwriting.

Any of these methods may be employed during the course of a trial and depending on the nature of the trial - and indeed the severity of the crime - it may also be necessary for the jury to visit the scene of the crime.
Visiting the Crime Scene

If the crime being tried in court is that of murder - and in particular a series of particular brutal murders - then it may be necessary for the jury to visit the scene - or scenes - of crime to gain more of an understanding into the nature of the killings.

This normally happens in trials of so-called serial killers; a serial killer is defined as an individual- 
or individuals - who have committed a series of murders using the same Modus Operandi (MO) over a defined timescale. Serial killers are normally creatures of habit and can return to the scenes of their crimes more than once, thus showing the jury these crime scenes can - in conjunction with expert testimony - can assist the jury in gaining valuable insights into their character and their motives.
Video Evidence

Video evidence is now employed in many courtrooms across the United Kingdom (and the U.S.A) as a means of protecting not only the identity of those giving evidence but also as a means of saving money. Witnesses may not be able to attend a trial for a variety of different reasons but may be able to attend their local court where a video link will provide them with two-way audio and visuals of the trial proper.

Also evidence recorded onto video such as those films recorded on digital camera or video camera may be submitted to the court as evidence. In instances such as terrorists attacks such evidence is invaluable in order to build up a picture of what happened before, during and after such an attack took place.

Again it is worth noting that all evidence submitted for a trial must be relevant and should not be based on supposition or hearsay; circumstantial evidence as it is known is not reliable and therefore both defence and prosecution counsels are likely to ask for its exclusion from any criminal proceedings.

Most of us will have heard the term Ballistics at some time or other - more often than not when we have been watching fictionalised accounts of police work on television or in the cinema.
What is Ballistics?

Ballistics is the area of Forensic Science that deals with firearms; how they are used, why they are used and why they are used frequently in the practice of murder.

What many people do not realise is that when a person is shot the wound and the condition of the victim can tell a lot about the nature of the weapon that has been used. Indeed if the weapon has been left at the scene of the crime - which sometimes happens when the perpetrator panics - the weapon itself can go a long way to providing valuable information as to the kind of person who has committed the offence.
Identifying a Weapon

Most guns have their own unique identifying features and even if the gun has not been left at the crime scene many degrees of information can be determined from the bullet, the nature of the wound and any residue that is left around it.

Bullets contain a mixture of gunpowder and cordite and these leave burn marks on the skin of the individual either wounded or killed, they also leave a fine residue on the fingers and hands of the individual firing the gun. These burn marks can signify closeness of the victim to the perpetrator, kind of weapon and also if the weapon has had any modifications made to it. Some weapons have been disarmed by having the firing pins and mechanisms removed but there are individuals who can 'reactivate' these weapons for use again.

Also, each weapon's barrel contains small ligatures and grooves, which, when a bullet is fired from them, make marks on the shell casing, which can be used as a means of identifying the make and model of gun if these shell casings are found at the scene.

It is also worth noting that an automatic - or semi automatic weapon - will expel shell casings as the weapon fires a round whereas a revolver will fire the round but retain the shell casing within the barrel (cylinder).
Investigating

The field of ballistics is able to identify rifling patterns, marks made by using suppressors (silencers), shell casings, powder burn and many other different areas relating to the use of firearms and the evidence they leave behind.

Indeed most ballistics experts will be able to tell you the particular weapon simply by the sound of it being fired. They will also be able to carry out distance and depth tests which include firing rounds of ammunition into water, sand and other substances to determine how close a person would have to be to receive a life threatening wound from a gun.

Ballistics is a very important part of the world of Forensic Science and much of its evidence is used in criminal proceedings. In some cases the use of ballistics research can prove a link between many different crimes carried out over a lengthy period of time. This is also an important function of the ballistics team as many weapons are passed and sold on between criminals during their life cycle.