Chapter 2
Legal Aspects of Investigation
LEARNING OBJECTIVES
 Explain the historical evolution of the laws of arrest and search and seizure from the Bill of
Rights through the Fourth Amendment.
 Describe and diagram the flow of constitutional rights to a defendant in a federal criminal
trial and a defendant in a state criminal trial.
 Outline the requirements of a valid arrest warrant.
 Describe whether a “John Doe” arrest warrant is ever valid, and if so, under what
circumstances.
 Define probable cause.
 Describe the evolution of the Exclusionary Rule.
 Explain the “Silver Platter” doctrine.
 Describe the reason for a search incident to a lawful arrest.
 Explain the limitations on the search of a motor vehicle incident to an arrest.
LEARNING OBJECTIVES continued
 Describe at least five circumstances that justify a search under exigent circumstances.
 Define the law enforcement policy issue that determines whether an inventory search is
lawful.
 Identify the primary requirement that makes a plain view seizure lawful.
 Describe the limitations of a stop and frisk encounter.
 Explain the circumstances that would cause application of the Fruits of the Poisonous Tree
doctrine.
The Fourteenth Amendment
 Provides the foundation for much of modern criminal procedure in the U.S.
 No state shall make or enforce any law which shall abridge the privileges and immunities of
citizens of the United States; nor shall any state deprive any person of life, liberty, or
property, without due process of law; nor deny any person within its jurisdiction the equal
protection of the laws.
 Granted federal government the power to tell the states what they could or could not do
The Fourteenth Amendment
Dual citizenship
 Gives the federal government the power to tell the states they cannot abuse the freedoms of
all U.S.. Citizens
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are
citizens of the United States and the state wherein they reside.
The Due Process Clause
 The due process clause provides, “…nor [shall any
person] be deprived of life, liberty or property without
the due process of law.”
The Fourth 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
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upon probably cause, supported by oath or affirmation, and particularly describing the place
to be searched, and the persons or things to be seized.
Sniffing Out the 4th Amendment
Florida v. Jardines (2012)
How much power does the Constitution entrust to our canine friends?
Is a dog’s sniff enough evidence to obtain a search warrant?
Arrest
 There are a number of definitions of the term arrest. They range from:
 “any interference with a person which, if not privileged, would constitute false imprisonment,”
 “interfering with the freedom of a person who is suspected of criminal conduct to the extent
of taking him to the police station for some purpose,”
 “the taking of custody upon sufficient and proper evidence for the purpose of prosecution.”
Ingredients of Arrest
There are three essential ingredients of an arrest:
1. Intention
 To take the suspect into custody
2. Authority
 Real or assumed (e.g., a defective warrant)
3. Custody
 Physical restraint or voluntary submission
Arrest Distinguished from Detention
There is a fine line between detention and arrest:
Detention is a temporary and limited interference with the freedom of a person for investigative
purposes.
Sometimes called investigative detention, it is also commonly referred to by law enforcement as a
“street stop” or “field interrogation.”
“Stop and Frisk”
 Patting down outer clothing
 Police suspect person being questioned may be armed and their safety is in jeopardy
Charging
A decision to prosecute
Usually made by the prosecutor (State Attorney’s Office)
Standard must exceed “probable cause,” and be “beyond a reasonable doubt.”
…and no warrant shall issue, but upon probable cause, supported by oath or affirmation, and
particularly describing the…person…to be seized. – 4th Amd.
Arrest Procedures
The laws of most jurisdictions permit an arrest in at least three and sometimes four types of
situations:
1. When a warrant has been issued.
2. When a crime is committed in the presence of an arresting officer.
3. When an officer has probable cause to believe that the suspect being arrested has
committed a felony.
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4. In statutorily created instances.
Arrest Warrant
 An arrest warrant is a judicial order commanding the person to whom it is issued or some
other person to arrest a particular individual and to bring that person promptly before a court
to answer a criminal charge.
Affidavit
 The warrant must be supported by an affidavit:
 a written statement of the information known to the officer that serves as the basis for the
issuance of the warrant.
 Blank warrants are not constitutionally valid.
 DNA profiles can be used when name of suspect unknown
Arrest Warrant
 Relieves law enforcement of the burden of proving the legality of the arrest
 Provides an independent evaluation of the sufficiency of the evidence

Herring v. U.S. (2009)
o The good-faith exception.
o The exclusionary rule does not apply when a police officer makes an arrest based
on an outstanding warrant in another jurisdiction, and the information is later
found to be incorrect because of a negligent error by that agency.
Affidavit continued
A police officer affirming to a judge the contents of his affidavit.
Contents of a Warrant
1. The authority under which the warrant is issued (the name of the state).
2. The person who is to execute the warrant (generally addressed to any peace officer of the
state).
3. The identity of the person to be arrested.
4. The designation of the offense.
5. The date, time, and place of the occurrence.
6. The name of the victim.
7. A description of the offense and how it occurred.
Probable Cause
 Probable cause is a difficult term to define because in no two instances are circumstances
identical.
o More than suspicion but less than actual knowledge.
o Suspicion plus facts and circumstances that would
lead a reasonable person exercising ordinary caution to believe that
a crime has been, is
being, or is about to
be committed.
Exceptions to the warrant requirement:
 Crimes committed in the presence of an officer
 Felony cases not committed in the officer’s presence provided reasonable grounds or
probable cause exists
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
Certain nonfelony cases even though the offense is not committed in the officer’s presence
o Domestic violence
o Shoplifting
Legal Searches
 As is true for arrests, the Fourth Amendment also only recognizes searches and seizures:
o by government agents
o under the authority of a warrant
 The United States Supreme Court recognizes judicially created exceptions.
 Until 1914, evidence obtained in an illegal search and seizure by federal law enforcement
officers was admissible in court
Search Warrant continued
Officers conducting a search warrant based on a warrant.
Legal Searches
 Weeks v. U.S. (1914)
o “federal exclusionary rule”
o “Silver Platter Doctrine”

Mapp v. Ohio (1957)
o Any evidence unreasonably searched and seized would no longer be admissible
in any court—state or federal
Legal Searches
Can be made
1. when a warrant has been issued;
2. with consent;
3. incident to an arrest;
4. of a motor vehicle;
5. when an emergency (exigent circumstances) exists;
6. to conduct an inventory.
Search Warrant
 A search warrant is:
 a written order
 in the name of the state
 signed by a judicial officer
 exercising proper authority
 directing a law enforcement officer to search for specific property and bring it before the
court
 Must particularly describe the place to be search
 Also applies to the things to be seized
 Cannot go outside the scope of the officer’s authority
Search Warrant
Persons found on the scene may not be searched unless they are first lawfully arrested.
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Consent Searches
One of most common searches arising today
 Officer asks for permission to search location
 If consent granted, officer may search
 If consent denied, no search may be made unless there is probable cause under one of the
other exceptions to warrant requirement
 Denial alone is not probable cause
 Consent must be voluntarily given
 May be withdrawn at any time
Motor Vehicles
1. If sufficient probable cause exists to get a warrant, but, because a vehicle is moveable, it
might be gone if time were taken to get a warrant, a warrantless search is justified
(Carroll v. U.S., 1925)
 Can search the entire vehicle, including the trunk
 A vehicle search is not reasonable if conducted pursuant to stopping a vehicle for a traffic
violation and writing a citation.
Motor Vehicles
2. A search may be made of the area under the arrestee’s immediate control when a police
officer makes a lawful custodial arrest of the occupant of an automobile (NY v. Belton,
1981)
 Any open or closed containers found in the passenger compartment can also be search
 Does not include the trunk
Exigent Circumstances
 The exigent circumstances exception recognizes a warrantless entry by law enforcement
officials may be legal when:
 There is a compelling need for official action
 No time to get a warrant
o Danger of flight or escape
o Loss or destruction of evidence
o Risk of harm to the public or police
o Mobility of a vehicle
o Hot pursuit
Conducting an Inventory
 Law enforcement agencies have the right and the obligation to inventory property taken from
a person arrested
 Includes a motor vehicle
 Inventorying contents of a trunk
Plain View Seizures
 If an investigator/officer is lawfully in a place and sees contraband or evidence in plain view,
the investigator may seize the evidence and it will be admissible.
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Stop and Frisk
Terry v. Ohio (1968)
 Officer McFadden sees Terry, Chilton, and Zucker walking around suspiciously. He stops
them, frisks them, and finds a gun.
 Gun was admitted at trial. OH Supreme Court dismisses the appeal, saying that no
substantial constitutional question was involved.
 Issue: Does admitting the gun violate Terry's rights under the Fourth Amendment (made
applicable to the states by the Fourteenth)?
 Holding: No. Affirmed.
Stop and Frisk
Terry v. Ohio (1968) continued
 Rule:
o It is a seizure if the officer has, by force or show of authority, restrained the liberty of
a citizen.
o The scope of a search must be strictly tied to, and justified by, the circumstances
which made it permissible.
o Specific and articulable facts are required.
 Reasoning: It would be unreasonable to deny that this was a seizure. It would also be
unreasonable to require police to take giant risks in their jobs. So, this rule is a balance
between those interests.
 Dicta: People aren't compelled to answer questions; failure to answer is not grounds for
arrest.
Plain View Seizures continued
Officer conducts a pat-down frisk for possible weapons.
Fruits of the Poisonous Tree
 Consequences of an unreasonable search and seizure.
 The fruits of the poisonous tree doctrine provides that evidence obtained from an
unreasonable search and seizure cannot be used as the basis for learning about or collecting
new admissible evidence not known about before.
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