1. Legal Aspects of Criminal Investigation: Arrest, Search and Seizure

2. Detention vs. Arrest
Detention: a temporary and limited interference with the freedom of a person for investigative purposes
Arrest: 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

3. Essential Ingredients of an Arrest
There are three essential ingredients:
Intention: the officer must have the intention of taking the suspect into custody
Authority: the officer must have the actual authority to make a legal arrest or at least believe this to be the case (ex: an investigator makes an arrest under a defective warrant but does not know about the defect)
Custody: the person arrested must come within the custody and control of the law

4. Situations in Which an Arrest is Permitted
Warrant: a judicial order commanding the person to whom it is issued to arrest a particular individual and bring that person before a court to answer a criminal charge
Crime is committed in the presence of an arresting officer
Probable cause: it is suspicion plus facts and circumstances that would lead a reasonable person exercising ordinary caution to believe that a felony crime has been, is being, or is about to be committed

5. Situations in Which an Arrest is Permitted (cont.)
Statutorily created instances: by legislation, states allow arrest in nonfelony cases even though the offense is not committed in the officer’s presence; examples are cases of domestic violence and battery

6. Arrest Warrant
In most cases, the warrant must be issued by a judge who personally reviews the facts to determine the existence of reasonable grounds
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

7. Contents in the Warrant
The authority under which the warrant is issued (the name of the state)
The person who is to execute the warrant (generally addressed to any peace officer of the state)
The identity of the person to be arrested
The designation of the offense
The date, time, and place of the occurrence
The name of the victim
A description of the offense and how it occurred

8. Example of a Warrant

9. Weeks vs. United States (1914)
In this federal case, Weeks was charged with federal crimes and evidence obtained without a search warrant was used to convict him
On appeal, the Supreme Court ruled that the evidence was not admissible and overturned the conviction
This became the basis for the federal exclusionary rule; but the states had no such rule
State officers could obtain evidence illegally and hand it over to federal agents; this became the “Silver Platter Doctrine”
In 1960, the Supreme Court prohibited the introduction of all illegally seized evidence

10. Mapp v. Ohio (1961)
In 1957, Cleveland police presented a “warrant” to Ms. Mapp and searched her house
Evidence was collected and Ms. Mapp was arrested
At trial Ms. Mapp was convicted, even though the search warrant was never produced
Her case was appealed to the Supreme Court, who decided in 1961 that any evidence unreasonably searched and seized would no longer be admissible in any court—state or federal

11. Search Warrant
A written order, in the name of the state, that is signed by a judicial officer exercising proper authority
Directs a law enforcement officer to search for specific property and bring it before the court
Must be based on probable cause established by a written affidavit prepared by the law enforcement officer
Must describe the place to be searched and what is to be seized

12. Warrantless Searches
There are instances when searches can be conducted without a warrant
Search with Consent:
if an officer asks if he can search a person, vehicle, etc. and the person says yes, the search may be conducted
if the person shares the space (i.e. a roommate in an apartment), only the space of the person giving consent can be searched
consent must be voluntary (can’t be obtained through threats or intimidation)
consent can be withdrawn at which point the search must stop

13. Warrantless Searches (cont.)
Search Incident to Arrest:
officers can search people who are being arrested
these searches are to protect police officers and preserve evidence
the area under the immediate control of the person being arrested can be searched to prevent the person from obtaining a weapon or destroying evidence
Search of a Motor Vehicle:
if there is sufficient probable cause to get a warrant, but because a vehicle is movable, the Supreme Court has ruled that the car can be legally searched without a warrant
when an officer makes a lawful arrest of the occupant of an automobile, the passenger compartment can be searched (the trunk cannot)

14. Warrantless Searches (cont.)
Exigent Circumstances: recognizes a warrantless entry by law enforcement officials when there is a compelling need for official action or there is no time to get a warrant (ex: danger of flight, loss or destruction of evidence, risk of harm to the public or police, and mobility of a vehicle)
Conducting an Inventory:
law enforcement agencies have the obligation to inventory property taken from an arrested person
the purpose is to protect the property of the arrested person

15. Plain View Seizure
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.

16. Stop and Frisk (Terry v. Ohio)
In this Supreme Court case, the Court ruled that under circumstances where a person is acting suspiciously and the officer is concerned about his own safety when approaching such an individual, the officer may pat down the outer clothing to determine if the person has a weapon even though there was no arrest
If a weapon is found, it may be seized and can be used as evidence
The officer can frisk for weapons only