Case Topics: Exclusionary Rule, Due Process

" . . . our holding that the exclusionary rule is an essential part of both the Fourth and Fourteenth Amendments is not only the logical dictate of prior cases, but it also makes very good sense. There is no war between the Constitution and common sense." —Justice Clark, speaking for the majority

Suspicious that Dollree Mapp might be hiding a person suspected in a bombing, the police went to her home in Cleveland, Ohio. They knocked on her door and demanded entrance, but Mapp refused to let them in because they did not have a warrant. After observing her house for several hours, the police forced their way into Mapp's house, holding up a piece of paper when Mapp demanded to see their search warrant. As a result of their search, the police found a trunk containing pornographic materials. They arrested Mapp and charged her with violating an Ohio law against the possession of obscene materials. At the trial the police officers did not show Mapp and her attorney the alleged search warrant or explain why they refused to do so. Nevertheless, the court found Mapp guilty and sentenced her to jail. After losing an appeal to the Ohio Supreme Court, Mapp took her case to the U.S. Supreme Court. The Court determined that evidence obtained through a search that violates the Fourth Amendment is inadmissible in state courts.

About the materials

These materials were developed for students of various skill levels, and teachers should choose the level that works best for their students.  Answers to the background questions, vocabulary, and activities can be found in the "Answers & Differentiation Ideas" tab under each case.

Background summary and questions to consider (by reading level)

Important vocabulary (by reading level)

Legal Concepts

  • Search and Seizure
  • Due Process

Other useful background information

Street Law Activities*

The Case

After the Case

* See the "Answers & Differentiation Ideas" tab for access to answers to the background questions, vocabulary, and activities.


Teaching strategies used


Planning time and activities

If you have one day . . .

  • Begin discussion by asking students to create a KWL chart (what they know, what they want to know, and what they have learned) about search and seizure. Discuss their responses in the "K" and "W" columns. Explain that you will begin studying Mapp after completing the "K" and "W" columns in order to complete the "L" column.

  • Read the background information (•••, ••, ) on the case as a class. Have students answer the questions that follow. Next, have students predict the outcome of the case.

  • For homework, have students read the excerpt of the majority opinion and answer the accompanying questions. Then have students complete the "L" column on the KWL chart and discuss as a class.

If you have two days . . .

  • Complete the activities for the first day. (Note to teachers: We recommend that you invite a community resource person, such as a police officer, judge, or lawyer, to assist in the activities described here for day two. Many of the scenarios are tricky and the answers can depend upon the nuances of state law.)

  • Complete the activity titled "When is a Search Warrant Not Necessary?

  • Next, complete the activity titled "Search Warrants: What Are They and How Do They Work?"

  • For homework, have students read "The Exclusionary Rule in a Computer-Driven Society" and complete the written response that appears at the end of the reading. (You may want to print out this activity for them instead of having them do it on the Internet, as there is a hotlink to the actual outcome in Arizona v. Evans, which you won't want them to see until they have completed the activity. There are several other hotlinks embedded in the text, but these links are there primarily for enrichment.)

  • On your last day, have students complete the "L" column on the KWL chart and discuss as a class.

If you have three days . . .

  • Complete the activities for the first and second days.

  • On the third day, discuss the outcome in Arizona v. Evans. Have students complete the activity titled "Friend or Foe? Debating the Exclusionary Rule, Part I." Review and discuss the answers.

  • On your last day, have students complete the "L" column on the KWL chart and discuss as a class.

If you have four days . . .

For select case materials and activities, Street Law provides answers and suggestions for differentiation.

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