4. Legal Limitations on Police behavior:
a) Police are authorized to use coercive and
intrusive measures in enforcing the law
 Legal use of force = defining element
 Legal constraints on police authority
b) Police are authorized to carry out
interrogations & evidence collection
 But basic rights to privacy & freedom
c) How to insure proper use of coercive
procedures by police?
4. Legal Limitations on Police behavior:
Major Issues
a) Search and seizure
 4th Amendment concerns
b) Interrogation and Self-incrimination
 5th Amendment concerns
 6th Amendment concerns
 The Miranda Rule
c) The Exclusionary Rule
a) Searches & Seizures:
 Key issue = 4th Amendment:
“The right of the people to be secure in their
persons, houses, papers, and effects, against
unreasonable searches and seizures, shall
not be violated, and no warrants shall issue,
but upon probable cause, supported by oath
or affirmation, and particularly describing
the place to be searched, and the persons or
things to be seized.”
 Implied right to privacy
a) Legal Searches & Seizures:
1) Searches with Warrant
– Obtaining a legal warrant  “probable cause” +
specificity (what & where)
– Executing a warrant  limits on where & how
2) Searches without Warrants (warrantless)
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Searches incident to lawful arrest
Consent searches – most common type of search
Plain view searches
Stop and Frisk
Automobile searches
Open fields & abandoned property
3) “Seizures” may refer to either people or
things
3) Seizures (of people & things) (cont.)
─ Seizures of people
•
Stops (“Terry stops”) – reasonable suspicion to stop,
inquire, and pat-frisk
─ “frisks” versus searches?
─ Detaining & restricting stopped persons
• Arrests (custody stops) – (1) probable cause to take
into custody (felonies) or (2) arrest warrant or (3) inview violation (misdemeanor)
 Allows for broader, more intrusive search
 Self-incrimination rights become active (Miranda)
• Note a “Continuum of Intrusion”  the more intrusive
the stop, the stronger the suspicion requirement
─ Constitutional Right-to-Privacy?
• Variable = some people have less expectation or rights
• May be waived in exceptional circumstances
b) Interrogations
 Key issue = 5th amendment’s protection
against self-incrimination
•
“No person . . . . shall be compelled in any
criminal case to be a witness against himself,”
 Additional issue = 6th amendment’s
guarantee of right to counsel
• “the accused shall enjoy the right . . . to have
the assistance of counsel for his defense.”
b) Interrogations
 For police, the freedom from selfincrimination and right to counsel apply
to any interrogations where a person
who is a “suspect” may supply selfincriminating info
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•
Supreme court has ruled these rights apply
from the point of arrest or initial suspicion
The suspected person must be aware of
their rights and of police suspicion of them
The Miranda Rule – informing the “suspect”
b) Interrogations (cont.)
 Two major forms of interrogation:
1) Custodial (in-custody) interrogation
– Physical or Constructive custody
– Miranda v. Arizona (1963) = the key
2) Field interrogation  lesser degree of
intrusion (stop-and-frisk actions)
– “Reasonable suspicion” applies here
– “Self-identification” requirement as an evolving
issue
3)
May also apply to physical/medical tests
– Depends on degree of intrusion
– DUI  “implied consent”
b) Interrogations (cont.)
 When is Miranda not required?
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General on-the-scene questioning
Volunteered statements
Questioning of witnesses
Field stops (stop and frisk cases)
Routine questions of drunk-driving suspects
During line-ups and photo-ID sessions
Statements to private persons
Suspect appearing before grand jury
A situational threat to public safety
c) What happens if search, seizure, or
interrogation is illegal?
• “Exclusionary Rule” (ER): Evidence seized illegally
cannot be used to convict  this applies deterrent
sanctions to improper police conduct
• ER was introduced in 1914 (Weeks v. U.S.) to apply
only to federal police actions
• Extended to all police in 1961: Mapp v. Ohio
• Has been since been moderated in later decisions
• Note: “Derivative Evidence rule” as an extension
– “Fruit of the poisonous tree” doctrine
• What are effects of the Exclusionary rule?
c) Important exceptions to the
Exclusionary Rule:
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Good Faith exception
Inevitable Discovery exception
Harmless Error exception
Independent Source exception
d) Evaluating the Exclusionary Rule
• Reasons for the rule?
• Argument against the rule?
• Actual effects of Exclusionary Rule on
policing?
– Substantial impact on standardization of police
practices
– Little impact on enforcement outcomes
– Effects appear to be largely symbolic (but
nonetheless important)
Evolving legal context of policing?
• 20th Century
– Explication of federal limits on policing (early decades)
– Application of federal restrictions to local police
(Warren Court in 1960s)
– Moderation & reduction in restrictions (in Berger and
Rehnquist Courts: 1970s, 1980s, 1990s, up to 2005)
• 21st Century
– Continued moderation of restrictions on police?
(Roberts Court) (but not always)
– Impact of drug war and anti-terrorism legislation has
introduced more complications
– Future changes = difficult to predict?