Criminal Evidence

1
Criminal Evidence

• The crime scene, the chain of custody
  requirement, and fingerprints as evidence
• Chapter 16

2
Obtaining evidence from a crime scene

• When a crime occurs in a public place such as on
  a street or sidewalk, law officers would not have
  to show authority such as consent, a search
  warrant, or an exigency to justify their entry

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Obtaining evidence from a crime scene cont..

• Private premises such as a home, apartment or
  office, police can only enter with consent or
  with a warrant
• Exigency-where a persons life or safety is
  endangered
• Officers can only stay in a place to search for a
  reasonable period of time

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Obtaining evidence from a crime scene cont.

• Mincey v Arizona- States there is no murder scene
  exception
• A police officer was shot in the head and killed
  during a drug raid on suspects apartment
• The apartment was seized and searched for 4 days
  and over 300 objects were taken for evidence
• US Supreme Ct overturned Arizona Supreme Ct
  Murder Scene Exception and stated a warrantless
  search of the apartment was not legal because a
  murder had occurred there

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What can police search for in premises where a
serious crime has recently occurred?

• Law officers may make a prompt warrantless search
  of the area to see if there are other victims or
  if a killer is still on the premises
• The police may seize any evidence that is in
  plain view during the course of their legitimate
  emergency activities

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Obtaining evidence

• Obtaining evidence after a hot pursuit entry into
  private premises
• Court holds that officers are under no obligation
  to delay a search if the failure to immediate
  search would gravely endanger them when looking
  for weapons
• Obtaining evidence in now or never exigency
  situations
• 1966 Schmerber v Calf created the implied
  consent laws of today Suspect was involved in a
  car accident where he and others were injured and
  he was suspects of intoxication

7
Obtaining evidence in emergency aid situations

• Evidence found when police are responding to an
  emergency may be used in criminal trials
• Police may aid physicians who are treating
  persons who have overdosed
• Anytime police receive a report of an emergency
  they are duty bound to search
• If police observe someone injured and unconscious
  in a home
• Police can stop and search cars where shots have
  been fired

8
Defendants must have standing to challenge the
use of evidence obtained from crime scenes

• To have standing and challenge the manner in
  which police obtained evidence from a crime
  scene, a defendant must show that he had a
  legitimate expectation of privacy in the crime
  scene

9
Protecting and searching a crime scene

• To prove that evidence is genuine and authentic
• Testify about where and how the object was
  obtained
• Identify the object by serial number if a serial
  number is on the object
• Identify the object based upon personal knowledge
  and observations
• If the evidence is not readily identifiable or is
  susceptible to alteration by tampering,
  substitution, or contamination, the party must
  establish a chain of custody

10
The chain of custody requirement

• Chain of custody-all persons who had possession
  of the evidence must appear as witnesses to
  testify that evidence such as fingerprints or
  illegal drugs had not been tampered with,
  substituted, or contaminated while the witness
  had custody and control of the evidence

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Chain of Custody Documentation

• Chain of custody is usually required for the
  following types of evidence
• Videotapes
• A crack pipe
• Suitcase full of marijuana
• Forensic evidence
• Shell casing
• Blood Samples
• Note found near victims body
• Human hair, fibers, forged check, etc..

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Failing to show a sufficient chain of custody

• To use evidence that could be subject to
  tampering, etc. the state must by the use of
  witnesses, establish a chain of custody to show
  reasonable probability that the evidence was not
  tampered with

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Situations not requiring a chain of custody

• A chain of custody is not required if the object
  to be used as evidence is not subject to
  alteration by tampering, substitution, or
  contamination
• Such as
• Most shoplifting and theft cases

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Fingerprints as evidence

• Latent fingerprints-fingerprints left by a person
  on a surface other than one designed for
  recording fingerprints
• The FBI has millions of fingerprints on file
• They receive more than 20,000 fingerprints a day
  from law enforcement agencies throughout the
  country
• Fingerprints are the most valuable common forms
  of evidence

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Obtaining fingerprints

• Persons in lawful police custody
• Los Angeles has 40 thousand arrests each month
• Person who served in the military
• Many government employees
• People who receive licenses for such occupations
  as bartending, driving a taxicab, working in
  private security, or obtaining a government
  security clearance

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Proving that fingerprints were impressed at the
time of the crime

• It is impossible to determine the age of a latent
  print
• The government must show that the fingerprints
  could only have been impressed at the time when
  the crime was committed

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Automated fingerprint identification systems

• 1985 AFIS was activated
• Largest database in the US is the FBI
• 41 million fingerprint files
• 24 million crime history records

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Other types of evidence

• Palm prints and lip prints
• Footprints and shoe prints
• Bite marks
• To use bite marks an expert witness must be used
  such as a dentist or forensic odontologist
• Tire tracks- In State v Tillman the manager of a
  Goodyear tire store was held to have enough
  experience to testify as an expert in recognizing
  tread patterns on tire tracks

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The End