1. Laws Governing Police Surveillance
Constitutional Law
12th Edition
The University of Adelaide, School of Computer Science
4 February 2019
Chapter 5
Laws Governing Police Surveillance
Chapter 2 — Instructions: Language of the Computer 1

2. Copyright © 2010, Elsevier Inc. All rights Reserved.
Introduction
To safeguard the privacy of innocent persons, the interception of wire or oral communications should be allowed only when authorized by a court [and] with assurances that the interception is 
justified and that the information obtained thereby
will not be misused.
—Congressional Findings, Omnibus Crime Control
and Safe Streets Act of 1968
Copyright © 2010, Elsevier Inc. All rights Reserved.

3. Copyright © 2010, Elsevier Inc. All rights Reserved.
Threshold Question
Does the activity in question constitute a search?
if yes, then it will require a:
warrant
interception order
other form of judicial approval 
if no, then:
police may conduct their investigations, without concern for the Fourth Amendment
there may be statutory requirements
Copyright © 2010, Elsevier Inc. All rights Reserved.

4. Supreme Court Decisions
Olmstead v. United States (1928)
decided that wiretapping did not constitute a search
not a violation of the Fourth Amendment
Katz v. United States (1967)
overruled Olmstead
“The Fourth Amendment protects people, not places”
warrantless wiretapping violates the Fourth Amendment
Copyright © 2010, Elsevier Inc. All rights Reserved.

5. Copyright © 2010, Elsevier Inc. All rights Reserved.
Legislation
Wiretap Act (Title III of the Omnibus Crime Control and Safe Streets Act of 1968):
wiretap order is required
amended to provide protection for electronic communication
Copyright © 2010, Elsevier Inc. All rights Reserved.

6. Non-Assisted Surveillance
How the Fourth Amendment applies:
exposed to public view
not protected
police, where lawfully present, may use natural senses
home
heightened protection
warrantless surveillance may not be conducted from inside curtilage
open field carries no protection
information voluntarily disclosed to third party
no protection
Copyright © 2010, Elsevier Inc. All rights Reserved.

7. Copyright © 2010, Elsevier Inc. All rights Reserved.
Hoffa Doctrine
The Fourth Amendment does not protect “a wrongdoer’s misplaced belief that a person to whom he voluntarily confides his wrongdoing will not reveal it.”
Copyright © 2010, Elsevier Inc. All rights Reserved.

8. Copyright © 2010, Elsevier Inc. All rights Reserved.
Electronic Tracking
How the Fourth Amendment applies:
public movements
“free zone” activity
no protection
objects inside a home or other location protected by the Fourth Amendment:
search warrant required
Copyright © 2010, Elsevier Inc. All rights Reserved.

9. Copyright © 2010, Elsevier Inc. All rights Reserved.
Detection Devices
How the Fourth Amendment applies:
devices capable of revealing only the presence of contraband
no protection
metal detectors and X-ray scanning machines
compliance with administrative search exception to warrant requirement
individualized suspicion
thermal sensors aimed at home
search warrant
Copyright © 2010, Elsevier Inc. All rights Reserved.

10. Copyright © 2010, Elsevier Inc. All rights Reserved.
Wiretap Act
a wiretap order is necessary to intercept a protected communication 
unless one of the parties consents
interception occurs:
when a device is used to acquire access to the contents of a protected communication 
in the course of its transmission
Copyright © 2010, Elsevier Inc. All rights Reserved.

11. What the Wiretap Act Protects
wire (communications containing the human voice that travel through wires at some point in transmission)
oral (communications carried by sound waves)
electronic (data transmitted over a wide range of mediums)
Copyright © 2010, Elsevier Inc. All rights Reserved.

12. What the Wiretap Act Limits
the crimes for which wiretap orders may be issued
the duration of wiretap orders to a maximum of:
30 days
attainment of objective
fresh application required to extend
disclosure and use of communications intercepted to:
furtherance of investigation
national defense and security
giving testimony in court
Copyright © 2010, Elsevier Inc. All rights Reserved.

13. What the Wiretap Act Requires
approval by a high-ranking official within the Justice Department before the application can be submitted to the court
proof that traditional investigative techniques:
have been tried and failed
appear unlikely to succeed
are too dangerous to try
establishment of probable cause
that wiretap orders be executed so as to minimize intrusions into communications not related to the investigation
Copyright © 2010, Elsevier Inc. All rights Reserved.

14. Wiretap Act Does Not Protect
conversations overheard naturally
targets who lack a reasonable expectation that communication is not being intercepted
a party consents to interception
Copyright © 2010, Elsevier Inc. All rights Reserved.

15. E-mail, Voice/Text Messages
Wiretap Act
protects interception of during the transmission stage only
Stored Wire and Electronic Communications and Transactional Records Act
protects after the message has reached its intended destination
also protects voice mail, text messages, and transactional records
provides a lower standard of protection than the Wiretap Act
Copyright © 2010, Elsevier Inc. All rights Reserved.

16. Copyright © 2010, Elsevier Inc. All rights Reserved.
FISA 
electronic surveillance conducted inside the United States for the purpose of gathering foreign intelligence
surveillance orders require probable cause that:
the target is a foreign power
the target is an agent of a foreign power
the target is a member of an international terrorist organization
surveillance order not required for international communications between persons inside the United States and persons overseas if the target is the person overseas
Copyright © 2010, Elsevier Inc. All rights Reserved.