Legal aspects of forensics

Developments in Forensic Science700s AD- Chinese used fingerprints to establish identity of

documents and clay sculptures~1000- Roman courts determined that bloody palm prints

were used to frame a man in his brother’s murder1149- King Richard of England introduced the idea of the

coroner to investigate questionable death1200s- A murder in China is solved when flies were

attracted to invisible blood residue on a sword of a man in the community

1670- Anton van Leeuwenhoek constructed the first high powered microscope

1776- Paul Revere identified the body of General Joseph Warren based on the false teeth he had made for him

1784- John Toms convicted of murder on basis of torn edge of wad of paper in pistol matching a piece of paper in his pocket

1859- Gustav Kirchoff and Robert Bunsen developed the science of spectroscopy

1864- Crime scene photography developed

Developments in Forensic Science

1879- Alphonse Bertillion developed a system to identify people using particular body measurements

1896- Edward Henry developed the first classification system for fingerprint identification

1900- Karl Landsteiner identified human blood groups1904- Edmond Locard formulated his famous principle,

“Every contact leaves a trace”1922- Francis Aston developed the mass spectrometer1959- James Watson and Francis Crick discover the DNA double

helix1977- AFIS developed by FBI, fully automated in 19961984- Jeffrey’s developed and used the first DNA tests to be

applied to a criminal case

Criminalists vs. Criminologists

Developments in Forensic Science

The Canadian Criminal Justice System

The Canadian ConstitutionStatutory LawCommon Law or Case LawCivil LawCriminal LawEquity LawAdministrative Law

Canadian Constitution

Statutory Laws

Common LawAlso known as case

law are made by judges

The Canadian Criminal Justice SystemCivil Law

Also known as private law

Criminal Law

2 main categories◦ Misdemeanor-

◦ Felony-

Equity LawRemedial or preventive law

Administrative Law• Laws established by governmental

agencies such as the IRS, Social Security Administration, or the military

The Canadian Criminal Justice System

CONSTITUTION ACT, 1982CANADIAN CHARTER OF RIGHTS AND FREEDOMS

 Whereas Canada is founded upon principles that recognize the supremacy of God and the rule of law:

Guarantee of Rights and Freedoms1. The Canadian Charter of Rights and Freedoms guarantees the rights and freedoms set out in it subject only to such reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society.

Fundamental Freedoms2. Everyone has the following fundamental freedoms:(a) freedom of conscience and religion;(b) freedom of thought, belief, opinion and expression, including freedom of the press and other media of communication;(c) freedom of peaceful assembly; and(d) freedom of association.

CONSTITUTION ACT, 1982Legal Rights

7. Everyone has the right to life, liberty and security of the person and the right not to be deprived thereof except in accordance with the principles of fundamental justice.8. Everyone has the right to be secure against unreasonable search or seizure.9. Everyone has the right not to be arbitrarily detained or imprisoned.10. Everyone has the right on arrest or detention(a) to be informed promptly of the reasons therefor;(b) to retain and instruct counsel without delay and to be informed of that right; and(c) to have the validity of the detention determined by way of habeas corpus and to be released if the detention is not lawful.

CONSTITUTION ACT, 198211. Any person charged with an offence has the right(a) to be informed without unreasonable delay of the specific offence;(b) to be tried within a reasonable time;(c) not to be compelled to be a witness in proceedings against that person in respect of the offence;(d) to be presumed innocent until proven guilty according to law in a fair and public hearing by an independent and impartial tribunal;(e) not to be denied reasonable bail without just cause;(f ) except in the case of an offence under military law tried before a military tribunal, to the benefit of trial by jury where the maximum punishment for the offence is imprisonment for five years or a more severe punishment;(g) not to be found guilty on account of any act or omission unless, at the time of the act or omission, it constituted an offence under Canadian or international law or was criminal according to the general principles of law recognized by the community of nations;

Legal Rights

CONSTITUTION ACT, 1982Legal Rights

(h) if finally acquitted of the offence, not to be tried for it again and, if finally found guilty and punished for the offence, not to be tried or punished for it again; and(i) if found guilty of the offence and if the punishment for the offence has been varied between the time of commission and the time of sentencing, to the benefit of the lesser punishment.

12. Everyone has the right not to be subjected to any cruel and unusual treatment or punishment.13. A witness who testifies in any proceedings has the right not to have any incriminating evidence so given used to incriminate that witness in any other proceedings, except in a prosecution for perjury or for the giving of contradictory evidence.

Steps in Pursuing Justice If a crime is committed these are the steps to take

while pursuing justice◦ Police investigate what happened◦ Information is collected◦ Crime scene is documented and searched for

evidence◦ All info is assembled into a report and sent to crown

attorney◦ Investigation continues until probable cause is

established◦ An arrest warrant is issued for the suspect◦ The suspect is arrested

Individual is booked, fingerprinted, photographed and informed about his/her rights

Federal Rules of EvidenceProbative

Material

Hearsay

Admissibility of evidence

The amount of evidence that makes it into court is a portion of the total evidence:

• Evidence left at crime scene• Evidence collected by investigators• Evidence that can be tested and produces results• Evidence allowed into court according to rules of evidence

All of the accused’s rights must be honoured in the conduct of the search. A violation of rights under the Charter may lead to the exclusion of otherwise admissible evidence from the trial if admitting it would “bring the administration of justice into disrepute”.

Admissibility of evidence

Authentication: Process for admitting objects as evidence.

Admissibility of evidence

Forensic evidence is circumstantial evidence.

Evidence generated through science is called forensic evidence.

Admissibility of evidence

The judge decides if the evidence can be entered into the trial, based on:

Admissibility of evidence

• Has the scientific theory or technique been tested?

• Has the scientific theory or technique been subjected to peer review and publication?

• What are the known or potential error rates of the theory or technique when applied?

• Do standards and controls exist and are they maintained?

• Has the theory or technique been generally accepted in the relevant scientific community?

Expert testimony

• Expert evidence should be excluded if the potential for prejudice substantially outweighs the probative value.

• Expert evidence should not be admitted where there is a danger that it will be misused or will distort the fact‐finding process. It should be outside the experience and knowledge of a judge and jury.

Identical scientific results can be presented differently in court.Must avoid being overly definitive or overly inconclusive.

Forensic Scientist Ethics

Example:“The gunshot was fired

at a distance of 48.2 cm from the victim.”

Problem:

Example:“The gun appeared to

be 2.2 metres from the wall.”

Problem:

Expert testimony

The Presentation of DNA Evidence

Admissibility Hearings• Direct Examination• Cross Examination Issues• Outside Experts

Courtroom ProceedingsTrial Presentation

• Direct Examination• Cross Examination

Issues• Redirect• Outside

Experts/Rebuttal WitnessesBE PREPARED!

Extensive documentation of analyses conducted.

Strict adherence to protocols◦ Trials can be one to two years after lab work

completed; thorough notes and adherence to the protocol greatly reduces expert witness’s uncertainty during testimony

Pre-trial consultations and meetings critical!

Cross Examination TopicsContamination at crime scene / during evidence collectionContamination by laboratoryError ratesWhen DNA was depositedConsent (sexual assault cases)Population databases/ethnic background of defendant“It was the brother/father/uncle/etc.”Reliability of the technology - quality control issues

The Presentation of Evidence

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