Not Guilty: Students Discover How Science Can Free the Innocent

For eighteen years, Dennis Williams was imprisoned for crimes he didn't commit. Then, while incarcerated on Illinois's death row in a cell located just steps from the electric chair, DNA tests helped prove his innocence. He was released from prison in 1996.

Credit: Corbis

At Mandarin High School, in Jacksonville, Florida, exploring wrongful convictions of people such as Dennis Williams has become part of a biology-class project that illustrates the crucial role science plays in our everyday lives. The project calls for students to research a specific incident of wrongful conviction and give a presentation that illustrates the role DNA evidence played as a crime-solving tool in the case.

Mandarin teacher Diane Wagers has used this project in her second-year biology class for six years, and she says many of her students become angry when they first learn about wrongful imprisonment. "They literally will jump out of their seats and ask, 'Why did this happen?'" Wagers says. Getting to the bottom of why innocent people are convicted, she notes, both motivates her students to learn about DNA testing and illustrates the practical application of the biological sciences.

Wagers makes the project part of her biology curriculum because she believes connecting science concepts to life outside of the classroom is essential to good teaching. "Biology is the study of life, and when students look at these issues of wrongful conviction, it comes alive for them," she explains. "It helps them remember what they've learned, because they see it is real."

Student Britney Schank agrees. "In every other class, you just learn about DNA, its structure, how it's built, and all the boring stuff," Shank says. The DNA-testing project, however, showed her more. "I saw how DNA affects people's lives and how it comes into play."

Introducing the Innocence Project

At the beginning of the assignment, Wagers conducts a mini-lesson on DNA and its uses, including the ways people employ it in criminal investigations. Although her Biology II students have a background knowledge of DNA, Wagers says it's often helpful to revisit basic concepts.

After the refresher on the subject, students choose to either work alone or with a partner to research the legal case of someone who has been exonerated by DNA testing. Wagers says she gives students the option to work with a partner because it promotes teamwork and allows students to collaborate with someone who may have strengths different from their own.

To get her students started on the research portion of the assignment, Wagers points them to the nonprofit Innocence Project [1], which lists nearly 200 case profiles online. Each profile provides a case summary and links to additional information about the common causes of wrongful convictions, such as the unreliable and limited science used prior to the advent of DNA testing. The site also features an archive [2] of audio and video clips that includes interviews with some of the people who've been exonerated.

As the students work, Wagers circulates around the room to ask questions and make sure they understand the science behind DNA testing. "When you go from group to group, you can sit right down and look at a kid and ask, 'Do you get this?'" Wagers explains. "You can tell right then whether they comprehend it." If Wagers believes a student lacks a clear understanding of the science, she provides him or her with additional instruction or invites the student to come in after school. If a number of students seem confused, she'll review concepts with the entire class or refer them to online tutorials [3] such as those created by the Dolan DNA Learning Center. Students also tutor one another.

Presenting the Facts

After an initial in-class work session, Wagers gives students two weeks outside of class to collect information on their case, organize the facts into a Microsoft PowerPoint presentation (Wagers provides an outline), and prepare a discussion of the role DNA played in the exoneration they studied.

During the class presentations, Wagers grades students according to their understanding of DNA and its relevance to the case they researched, as well as the overall quality of their presentation. (See her grading rubric [4].) Students who worked in pairs must make a presentation together, and both members need to be able to answer follow-up questions.

At the close of the project, Wagers holds a debriefing discussion (see "Diving into DNA: Content and Context" below for topic ideas). For example, Wagers will ask students to talk about the cases they profiled and discuss whether they think DNA testing in criminal cases should receive public funding. Wagers says these conversations bring out a variety of responses from the students.

For some, the power of DNA testing makes a big impression: Several students jokingly tell Wagers they will never commit a crime now because, with DNA testing, they know they'll get caught. Others truly take the lesson to heart. For instance, one of Wagers's students has contacted the Innocence Project to help a relative he feels was wrongfully convicted. "He is taking something we've studied and putting it to use," Wagers says.

Cari Ladd, who lives in Jacksonville, Florida, writes articles, develops curricular materials, and manages the production of media resources.