In crime dramas like CSI, we often notice police officers gathering large amounts of weapons and shell in clear plastic bags. These bags have ‘evidence’ clearly marked on their cover, and are later used to convict the suspect. Driving past a real world crime scene, we similarly observe police officers sectioning off pieces of land or property with caution tape. This tape serves the purpose of keeping the public out of harms way, but also to ensure evidence remains unaltered from its original state. It must remain unaltered as it usually determines the guilt or innocence of the individual accused of the crime.


To put forward evidence, means to have information to be used in order to prove or disprove a certain matter of fact.

The law of evidence uses rules and legal principles that control the proof of facts in legal proceedings. These rules and principles determine what can and cannot be considered evidence, and how much weight is to be given to each piece of evidence. Evidence law is also concerned with the type of proof, quality, and quantity required.

The law of evidence has two main purposes in our criminal justice system. Firstly, this law establishes a set of principles that work to take out facts of no use to the decision maker. In doing so, it helps decision makers like judges or the jury make unbiased conclusions. Secondly, evidence law helps reduce the large amount of information coming before the decision makers; it expedites legal proceedings. In addition, judges exercise a significant amount of discretion for what can and cannot be considered evidence during trial.

In furthering our understanding evidence, It is important to understand the burden of proof as it relates to the criminal justice system. The burden of proof is a party’s obligation to prove something is the case. In the criminal court, this burden or ‘onus’ is placed up on the Crown attorney, who must prove that an accused person has committed the alleged offence. The Crown attorney does this with the aid of evidence. In court, the accused is presumed innocent. In criminal court, the standard of proof is ‘beyond reasonable doubt’. The Crown attorney must be able to prove the accused is guilty beyond reasonable doubt in order to get a conviction or in the youth criminal justice system a finding of guilt.

There are three different forms of evidence. The first is ‘real evidence’, which consists of things that are tangible. This type of evidence includes physical objects such as tape recordings, printouts, and photographs. In order for real evidence to be used in court, it must be relevant, and trustworthy. This also includes ‘demonstrative evidence’ such as charts, models, and experiments.

The second form of evidence is ‘documentary evidence’. This type of evidence includes digital tape recording, business and personal records, court documents, video clips, and computer records. For documentary evidence, there is a requirement that it must be the original copy or form—unless unavailable—this is called the ‘best evidence rule’. All documentary evidence is established as authentic and relevant prior to their use. This is done through the use of affidavits, or a testimony.

The third type of evidence is ‘testimonial evidence’, also known as oral evidence. This evidence is given viva voce, or through oral speech. Testimonial evidence is received through answers to questions asked mainly by Crown attorneys and Defense counsels. For instance, when a police officer is answering the questions of a lawyer on the witness stand, he or she is testifying for or against the accused. Any witness that testifies must give an oath or affirmation prior to giving their evidence, they must be personally present in court, and are subject to cross-examination.

If you are being investigated as a suspect for a criminal offence:

Youth who are charged with an offence under the age of eighteen are dealt with in accordance with the Youth Criminal Justice Act. It is important for young people who are accused with an offence to know that if he/she is being investigated for a charge AND HAVE NOT BEEN CHARGED he/she have no obligation to provide evidence to the investigating officer. This includes answering any questions. You have no obligation to go to a police station for questioning unless you arrested and taken to the station. Justice for Children and Youth recommends that youth to do not make a statement to the police.  The police have a burden to prove their case against you – you have no legal obligation to assist them. Anything that you say to a police officer can and will be used against you as evidence. The police officers will take notes of everything you say and provide this as evidence to the Crown attorney to be used against you.

If you are charged with a criminal offence:

When an accused attends to court for their first court appearance, if it is ready, they will be provided with disclosure. Disclosure is a package that includes all the evidence that was used by the police to lay the charge against the accused. This will include all of the police officers notes, any statements taken by witnesses/victims, DVD’s of footage from security cameras/filmed statements, etc. In the Youth Criminal Justice System the Crown attorney is obligated to provide all disclosure to a young person who has been charged with an offence.

Evidence has a significant role in the daily works of our criminal justice system. It ensures that all useful and valuable information gets placed in front of decision makers, like the Judge or Jury. The methods we use in court proceedings today have been developed over many decades, and attempt to ensure a fair and unbiased resolution to all legal disputes.

Information in this blogpost gathered from: “Rules of Evidence: A Practical Approach” by: Doug Cochran, Michael Gulycz, & Mary Ann Kelly

This blog post was written by Shawn Malik, a volunteer on JFCY’s PLE team. All legal content was reviewed by a JFCY staff lawyer.