CJ302 CJ302 Aguilar v. Texas, Illinois v. Gates Name Class Date Professor CJ302 Aguilar v Texas, Illinois v Gates In the case of Aguilar v. Texas, Illinois v. Gates and Spinelli v. United States a question arose about probable cause involved in the Fourth Amendment search. In Aguilar and Spinelli the Supreme Court ruled that the two prong test is needed to satisfy the requirement of probable cause in order to obtain a search warrant from a judge while in Illinois the Supreme Court overruled the need for the two prong test, which consists of reliable information from a credible source, in favor of the totality of the circumstances rule. In the case of Aguilar v. Texas two police officers obtained a search warrant from a judge in order to search the home of the petitioner Aguilar who was suspected of possessing heroin, marijuana, and other illegal drugs. The constitutional question arose concerning the probable cause used by police to obtain the warrant which only consisted of a statement by the officers that said they had reliable information of the defendant’s criminal behavior from a credible person (Kelly, 2007). After being found guilty of possession of heroin Aguilar appealed the ruling base on the objection to the introduction of evidence obtained as a result of the execution of the warrant. The petitioner appealed to the Supreme Court after being overruled by the Court of Appeals citing that the police did not have probable cause to conduct a search of his home. The Supreme Court agreed with the petitioner and the trial court’s decision was reversed and remanded based on the fact the warrant should never been issued because the magistrate did not base the probable cause for the warrant on reliable information from a credible source. This ruling in turn resulted in a two prong test to determine if there is probable case present to issue a warrant. The case of Spinelli v. United States further expanded this test finding that in order for a judge to issue a warrant as the result of an informant's tip, the state must present specific facts as to the credibility and reliability of the informant and the informant’s testimony. While the two prong test was established in Aguilar in Spinelli it was determined that even while collaborating evidence is present the credibility of the source must also be present in order for the court to approve a search warrant. In the case of Illinois v. Gates the police received an anonymous letter that stated the petitioner and other defendants were planning to traffic drugs from Florida to Illinois. After receiving the letter the police first corroborated the tip by observing the defendants engaging in the activities identified in the letter before requesting a warrant from a judge. The petitioner appealed but the Supreme Court ruled where an anonymous tip is corroborated with actual police finding, a “totality of the circumstances” approach is the best m.

1. CJ302
CJ302 Aguilar v. Texas, Illinois v. Gates
Name
Class
Date
Professor
CJ302 Aguilar v Texas, Illinois v Gates
In the case of Aguilar v. Texas, Illinois v. Gates and Spinelli
v. United States a question arose about probable cause involved
in the Fourth Amendment search. In Aguilar and Spinelli the
Supreme Court ruled that the two prong test is needed to satisfy
the requirement of probable cause in order to obtain a search
warrant from a judge while in Illinois the Supreme Court

2. overruled the need for the two prong test, which consists of
reliable information from a credible source, in favor of the
totality of the circumstances rule.
In the case of Aguilar v. Texas two police officers obtained
a search warrant from a judge in order to search the home of the
petitioner Aguilar who was suspected of possessing heroin,
marijuana, and other illegal drugs. The constitutional question
arose concerning the probable cause used by police to obtain the
warrant which only consisted of a statement by the officers that
said they had reliable information of the defendant’s criminal
behavior from a credible person (Kelly, 2007). After being
found guilty of possession of heroin Aguilar appealed the ruling
base on the objection to the introduction of evidence obtained
as a result of the execution of the warrant.
The petitioner appealed to the Supreme Court after being
overruled by the Court of Appeals citing that the police did not
have probable cause to conduct a search of his home. The
Supreme Court agreed with the petitioner and the trial court’s
decision was reversed and remanded based on the fact the
warrant should never been issued because the magistrate did not
base the probable cause for the warrant on reliable information
from a credible source. This ruling in turn resulted in a two
prong test to determine if there is probable case present to issue
a warrant.
The case of Spinelli v. United States further expanded this
test finding that in order for a judge to issue a warrant as the
result of an informant's tip, the state must present specific facts
as to the credibility and reliability of the informant and the
informant’s testimony. While the two prong test was established
in Aguilar in Spinelli it was determined that even while
collaborating evidence is present the credibility of the source
must also be present in order for the court to approve a search
warrant.
In the case of Illinois v. Gates the police received an
anonymous letter that stated the petitioner and other defendants
were planning to traffic drugs from Florida to Illinois. After

3. receiving the letter the police first corroborated the tip by
observing the defendants engaging in the activities identified in
the letter before requesting a warrant from a judge. The
petitioner appealed but the Supreme Court ruled where an
anonymous tip is corroborated with actual police finding, a
“totality of the circumstances” approach is the best method for
determining probable cause (Stevens, 2006). The totality of
circumstance replaced the reliability/credibility test in favor of
looking at all of the circumstances involved in the case to
determine probable cause.
After reviewing all three decisions by the Supreme Court the
ruling made in Aguilar and Gates establishing a two prong test
provides the best protection for the Fourth Amendment Right of
the citizen and relied less on the common sense of the judge as
well as providing stricter standards for obtaining a search
warrant. While the judge should always look at the totality of
the circumstances if the source is not credible despite all of the
reliable evidence produced by police the search should not be
allowed.
Because justice is not a search to make someone look guilty
but rather a tool used to ensure a guilty offender goes to jail for
their crimes probable cause should rely solely on reliable
evidence form a credible source. For example in the case of
Gates if the anonymous letter, the source that cannot be proved
to be credible, had never been sent to the police what evidence
would the police have that suspicious behavior was occurring.
Observing suspicious behavior that aligns with is source that is
not credible does not create probable cause.
While there are many definitions for probable cause but the
only definition that should count is the one that provides the
most protection for the Fourth Amendment Right o the citizen.
Probable cause is a reasonable belief that a citizen is engaging
in criminal behavior and the proof being offered by the police is
based on reliable and credible evidence. Based on the totality of
circumstances only the reliability is necessary and the
credibility of the sources is not a necessary factor in

4. determining probable cause.
References
Kelly, P. (2007). Fourth Amendment Summaries: Cases of the
1960’s. Retrieved February 3,
2012 from
http://www.fourthamendmentsummaries.com/cases/1960s_cases.
html
Stevens, M. (2006). Search and Seizure: A Guide to Rules and
Requirements, Tests, Doctrine,
and Exceptions. Retrieved February 3, 2012 from
http://faculty.ncwc.edu/mstevens/410/410lect14.htm