2 The Science in Forensic Science 1 Observe a problem or questioned evidence and collect objective data2 Consider a hypothesis or possible solution to the problem based on observation, giving direction to the work plan. This step inductive reasoning, experience and imagination.3 Examine, test, and analyze to support or refute a hypothesis.4 Use deductive reasoning to make a determination as to the significance of the evidence.5 Evaluate and verify all evidence. This step is especially critical to a forensic scientist because someone’s liberty can depend on the work. All possible errors must be stated. Consideration must be given to standardization, reproducibility, validity, reliability, and accuracy.
3 Civil Law vs Criminal Law Civil law- law that deals with noncriminal suits brought to protect or preserve a civil or private right or matter Criminal law- regulation and enforcement of rights, setting acceptable limits of conduct in society
4 Individual Rights Guaranteed by the Bill of Rights The right to be presumed innocent until proven guiltyThe right not to be searched unreasonably, either on one’s person or in one’s homeThe right not to be arrested without probable causeThe right to unreasonable seizure of personal propertyThe right against self incriminationThe right to fair questioning by policeThe right to protection from physical harm throughout the justice processThe right to an attorneyThe right to trial by juryThe right to know any charges against oneself
5 Individual Rights Guaranteed by the Bill of Rights The right to cross examine prosecution witnessesThe right to speak and prevent witnessesThe right not to be tried again for the same crimeThe right against cruel and unusual punishmentThe right to due processThe right to a speedy trialThe right against excessive bailThe right against excessive finesThe right to be treated the same as others, regardless of race, gender, religious preference, country of origin, and other personal attributes
6 Miranda Rights The following is a minimal Miranda warning: You have the right to remain silent. Anything you say can and will be used against you in a court of law. You have the right to speak to an attorney, and to have an attorney present during any questioning. If you cannot afford a lawyer, one will be provided for you at the government’s expense.
7 Types of CrimesViolation- any time a breach of a law has a taken placeCan be minor or major crimesCrimes are classified as infractions, misdemeanors, or feloniesInfractions- violation of a rule or law that is not punishable by prisonMisdemeanors- a minor crime, less than a felony.punishable by no more than one year in jailFines usually range from $250 to $2500Felony- more serious crimes that carry stiffer penaltiesPunishable by more than 1 year to life in prison or even death penalty
8 Steps in Pursuing Justice Crime is reported or discovered…. If crime observed by police officer then can go straight to arrest.Police arriveInvestigation by policeProcessing of crime sceneSearch and processing of evidencedocumentationSuspect identifiedProbable cause = situation in which a reasonable and prudent person, viewing the available information, would conclude that a crime has been committed and that the suspect committed it<<<<If probable cause…Arrest warrant obtained and bookingMiranda Rights ReadBooking= a police procedure following arrest that records basic information about the suspect, a photograph, and fingerprints and perhaps includes a lineupJail or BailArraignment- the first act in a criminal proceeding, where the defendant where the defendant is brought before the court to hear charges and enter a pleaUsually within 72 hrs of arrestPleas can be guilty, not guilty, not guilty by reason of insanity, double jeopardy, or nolo contendere (no contest- admit no guilt or innocence yet accept punishment as though he or she was guilty)
9 Steps in Pursuing Justice For FeloniesFor MisdemeanorsTrialConviction or acquittalIf convicted sentencingIf acquitted then releasedPreliminary or evidentiary hearingNo juryJudge hears evidence against defendantRight to cross examination and to produce favorable evidenceJudge decides to proceed to trial or dismiss or reduce charges due to insufficient evidenceSome states may use grand jury instead of preliminary hearingGrand jury consists of individuals sworn in to hear evidenceOnly prosecutor presents evidence, no cross examinationJury decides by majority vote to indict or not indict suspectIndict = formally accuseTrialIf convicted followed by sentencing hearing and prison or probationPossible opportunity for appealif acquitted then released
10 Facets of GuiltTo prove a case, the “MMO” must be established; it must be shown that the suspect had:Motive—person had a reason to do the crime (not necessary to prove in a court of law)Means—person had the ability to do the crimeOpportunity—person can be placed at the crime scene
11 Burden of ProofIn US, a person is presumed innocent until proven guiltyBurden of proof is on prosecution in criminal court casesIf there is reasonable doubt that defendant committed crime then jurors are instructed to vote not guiltyTakes all 12 jury members to vote guilty to convictOnly 50% of trials lead to conviction of defendentOnly 25% of trials lead defendant serving a year or more in jail/prison
12 Plea BargainingPlea Bargaining- an agreement in which a defendant pleads guilty to a lesser charge and the prosecutor in return drops more serious charges to avoid the cost and time of trialCan occur at many parts of the judicial processAbout 90% of criminal cases are plea bargained
13 Federal Rules for Evidence In order for scientific evidence to be admitted in a court of law, it must be:Probative: actually proves somethingMaterial: addresses an issue that is relevant or significant to the particular crimeHearsay- testimony given by a witness who relates not what he or she heard, saw, or knows personally, but what others have saidKnowledge is dependent on credibility of the person who first made the statement and is not considered reliable as it is not taken under oath and does not allow for cross examination.NOT ADMISSABLE in CRIMINAL TRIALS yet IS ADMISSABLE in CIVIL SUITS
14 Admissability of Evidence The Frye StandardFrom the 1923 case Frye v. United StatesScientific evidence is allowed into the courtroom if it is generally accepted by the relevant scientific community (particular field of study.)---The Frye standard does not offer any guidance on reliability.---The evidence is presented in the trial and the jury decides whether it has significance to the case or not.
15 Admissibility of Evidence The Daubert Ruling- revision of Frye StandardFrom the 1993 case Daubert v. DowThe judge decides if the evidence can be entered into the trial. Admissibility is determined by:1) Whether the theory or technique can be tested2) Whether the science has been offered for peer review3) Whether the rate of error is acceptable4) Whether the method at issue enjoys widespread acceptance5) Whether the theory or technique follows standardsHelps keep junk science (pseudoscience) out of courtroomFederal Ruling yet states are expected to use
16 Expert WitnessExpert Witness- person specializing in a particular techinical or scientific area of studyThe expert witness presents scientific evidence in court. He/She will:Establish credibility through credentials, background experience.Evaluate evidence.Render an opinion about the evidence (whether or not it incriminates defendant)The court or judge may accept or reject theopinion’s significance.Both prosecution and defense can present expert witnesses