The Crime Scene

Crime Scene

When the police arrive at the crime scene they usually do three things:

Call an ambulance and assist any injured people.

Call for help or backup if needed.

Search the crime scene for witnesses, the perpetrator or evidence.

Crime Scene

The police establish two boundaries to protect the crime scene.

The center is where the incident occurred. They also create a perimeter to keep people from entering.

Crime scenes are preserved for three reasons:

To allow for a thorough search of the area

To collect physical evidence

And to ensure evidence collected is useable in court.

Crime Scene

Police protect and preserve evidence by documenting the scene carefully and accurately.

Investigators keep a police log which is a written record of what each officer has witnessed at a crime scene or has learned from questioning witnesses or suspects.

The Crime Scene

There are four types of police officers involved at a crime scene.

The first is the Patrol Officer who is responsible for a certain area or “beat”. He or she is usually the first officer on the scene. They establish the perimeter by wrapping yellow tape and conduct questioning.

The Crime Scene

The Scenes of Crime Officer is trained in evidence collection. They take photographs, fingerprints and foot impressions along with blood and hair evidence.

The Criminal Identification Officer is responsible for searching the scene for physical evidence and sending it to the laboratory for analysis.

The Crime Scene

The Criminal Investigations Officer is dressed in plainclothes and is specialized in a particular area such as homicide or robbery.

They supervise the whole investigation, interview witnesses, interrogate suspects, draw conclusions from physical evidence, and arrest suspects.

Questions

List the three tasks the police must complete when they arrive at the crime scene?

What two boundaries are established by police? How does this help in their investigation?

Why do police keep a log of their activities at a crime scene?

What are the 4 types of officers involved at a crime scene? What does each do?

The Crime Scene

Physical Evidence may defined as any object, impression, or body element that can be used to prove or disprove facts relating to an offence.

Forensic Science is the application of biochemical and other scientific techniques to criminal investigation.

Crime Scene

Often at the scene of a crime impressions are left. Impressions are marks or patterns caused by different objects such as fingers, gloves, shoes, tires, or tools.

Crime Scene

Impressions have two characteristics: class characteristics and individual characteristics. Class Characteristics are general attributes of an object such as type, make, model, size, and style. Individual Characteristics deal with specific traits of an object such as tire ware or a scratch on a car.

Crime Scene

Fingerprints are patterned marks left on a surface by a fingertip. Prints are unique to each individual and never change.

There are two types of fingerprints: Visible and latent. Visible prints can be seen as where latent prints must be dusted or illuminated.

Crime Scene

Crimes against people usually result in the loss or transference of bodily fluids.

Police can use these fluids along with hair and skin samples to identify a persons DNA.

DNA is like fingerprints and is unique to every individual.

Crime Scene

The proper labeling of evidence is important so it can be identified at a later date.

Police officers establish a proper chain of custody for the evidence or a written record of everyone that has handled the evidence.

A chain of custody must show: Who had contact with the evidence

The date and time the evidence was handled

The circumstances and reasons for the handling of the evidence

What changes were made to the evidence

Crime Scene

All evidence collected at the scene of the crime is tagged and placed in and “evidence package”. The following information usually appears on both the tag and the exterior of the package: Brief description Police case number Date of collection Location of collection Brand name of the item Serial number or clothing information Name and badge number of the officer collected it Destination of the evidence

Crime Scene

A person who is detained by a police officer is taken into custody without the use of physical restraint.

The police usually detain a person for such things as questioning. The person being detained must be informed of the reasons for the detention and their right to retain counsel (lawyer).

Crime Scene

Police interrogate or ask a suspect questions with four goals in mind:

To get a description of the incident

Information about the time before the incident

The details around the offence

What happened after the offence

Crime Scene

If a person is arrested they are formerly taken into police custody.

In order for an arrest to be lawful the police must: Identify themselves as a

police officer

Advise the accused they are under arrest

Inform the accused the charges

Physically touch the person to indicate they are in custody.

Questions

1. What three things do police officers have to do when they arrive at a crime scene?

2. Why is the documentation of evidence important?

3. What four things do police have to do when they arrest a person?

4. What four pieces of information are police looking for when they question someone?

5. Why would someone want a lawyer present when being questioned?

Crime Scene

In order for a police officer to arrest someone they need reasonable grounds.

For example if Wendy was sitting in a car with bags full of money after a nearby bank was robbed. The police would have reasonable grounds to arrest her.

Crime Scene

The police have three methods of apprehending an offender:

An appearance notice is given at the scene of a crime that is less serious.

A summons is a legal document given to a person who the police believe will not appear in court voluntarily.

An arrest warrant is a legal document giving the police the authority to arrest or detain a person who is suspected of having committed a crime.

Crime Scene A citizen’s arrest is an arrest without a

warrant by any person other than a peace officer.

Section 494 of the Criminal Code says

Anyone may arrest without warrant

A person found committing an indictable offence

A person who 1) has committed a criminal offence 2) is escaping from and pursued by a person who has the authority to arrest.

Anyone who is

The owner of property

A person authorized by the owner of property may arrest a person he finds committing a criminal offence on or in relation to that property.

Questions

1. __________ To be taken into custody without physical restraint.

2. __________ The person being detained must be informed of these two things.

3. __________ In order for a police officer to arrest someone they need…

4. __________ Issued by police at the scene of a crime.5. __________ Issued to someone who is suspected of

not going to show in court.6. __________ A legal document allowing police to arrest

someone.7. __________ An arrest without a warrant by anyone

other than a peace officer.

Crime Scene

The police do not need a warrant to search a person they just arrested.

The arrested person does not have to supply the police with a breath, blood , or urine sample unless they are arrested for impaired driving.

The police are allowed to conduct strip searches under very strict guidelines.

Crime Scene

In order to search a dwelling the police need to obtain a search warrant.

The search must be conducted between 6:00am and 9:00pm and the police must identify themselves and provide the warrant.

In the case where police suspect a person of having illegal drugs they may search buildings without a warrant. They also may search a dwelling without a warrant if they believe it prevents imminent danger or the destruction of evidence.

Police are also allowed to search vehicles without a warrant.

Questions

1. __________ Needed to search a house.

2. __________ Hours in which a house can be searched.

3. __________ These can be searched without a warrant.

4. __________ If this is present in the house the police do not need a warrant.

5. __________ Police are allowed to conduct these under strict guidelines.

Crime Scene

Once a person has been arrested, fingerprinted, and photographed, the police will often release the accused until the trial.

If the police are not afraid of the accused fleeing trial they will just have them sign a promise to appear. If they fail to show an arrest warrant will be issued.

In some cases the accused may be asked to sign arecognizance-which is a promise to appear or a fine may be charged. A surety, a person willing to pay the fine in case the accused doesn’t show, may also be asked for.

Police will try and keep dangerous offenders in jail until trial. In this case a suspect can post bail. Bail is a some of money

Review

Definitions: Appearance Notice Search Warrant

Arrest Summons

Detention Chain of Custody

Fingerprint

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