Types of Evidence

What Is Evidence?

Evidence is any information presented to a court to prove or disprove a fact that is in dispute. The Alberta Basic Security Training (ABST) curriculum expects a security professional to recognize the main categories of evidence, because a guard is often the person who first encounters, preserves, or documents it. Misclassifying evidence — for example, treating hearsay as if it were direct proof — can lead to it being excluded and can weaken the Crown's case.

The Six Core Categories

Canadian courts generally recognize the following categories of evidence. Each has a different path to admission and a different weight with the trier of fact (the judge or jury).

---

Direct Evidence

Direct evidence is the strongest form of proof because it requires no inference. If a security guard personally observes a person spray-painting a wall, the guard's testimony — "I saw him spray the wall" — is direct evidence of the act. Direct evidence is still subject to credibility testing: cross-examination may challenge the guard's vantage point, lighting, distance, or attention.

A guard who did not see the event cannot give direct evidence of it. Saying "I arrived and the wall was already painted" is direct evidence of the wall's condition, but it is only circumstantial evidence of who painted it.

Circumstantial Evidence

Circumstantial evidence proves a fact from which the court may infer another fact. It is often more reliable than direct evidence — fingerprints do not misremember, and surveillance footage does not blink — but it always requires a logical bridge between the proven fact and the inferred fact.

A guard who finds a suspect hiding behind a dumpster, breathing heavily, with a crowbar in hand, has not seen a burglary. The facts observed (concealment, exertion, possession of a tool) are circumstantial evidence from which a court may infer the suspect committed or intended the burglary.

Hearsay and Its Exceptions

Hearsay is an out-of-court statement offered for the truth of what it says. The hearsay rule exists because the opponent did not have a chance to cross-examine the original speaker when the statement was made, and the speaker was not under oath. Hearsay is generally inadmissible.

Security guards encounter hearsay constantly. A store manager tells you, "Employee X told me she saw the customer steal." If you repeat that chain on the stand to prove the theft, you are offering hearsay. The correct practice is to identify the person with direct knowledge so that person can testify.

Canadian law recognizes exceptions to the hearsay rule. The most common exceptions a guard will meet include:

• Statements made by a party to the proceedings (admissions against interest) — if the accused said "I took it," that may be admissible against them
• Spontaneous utterances made while the declarant was under the stress of a startling event
• Business records made in the ordinary course of business, including a guard's notebook and incident reports when properly kept
• Dying declarations and certain res gestae statements

A guard should not decide on the street whether something is admissible — that is the court's job. The guard's job is to record the statement accurately, identify who said it, and relay it to police.

Documentary Evidence and the Guard's Notebook

Documentary evidence includes any document offered to prove its contents. For a security guard, the most important documentary evidence is the notebook — the contemporaneous, handwritten record of observations and actions — and the incident report prepared from it.

The notebook is powerful because it was made at or near the time of the event, before memory faded and before the story could be shaped. To keep it admissible and useful, a guard must:

• Write entries during or immediately after the shift, not from memory days later
• Use permanent ink, not pencil
• Never tear pages out, alter entries, or leave gaps
• Correct mistakes with a single strikethrough that leaves the original readable, initialled and dated
• Store the notebook securely and treat it as a potential exhibit

Physical (Real) and Trace Evidence

Physical evidence — sometimes called real evidence — is a tangible object connected to the event: a weapon, a stolen item, a broken lock. Trace evidence is the subset of physical evidence that is small or microscopic: fibres, fingerprints, hair, blood, gunshot residue, footwear impressions.

A guard does not collect trace evidence in the way a police forensic technician does, but a guard's actions determine whether trace evidence survives. Touching a door handle, walking through blood, or allowing a crowd to trample footwear impressions can destroy the very evidence that would have identified a suspect.