Using QR Codes in Forensic Science

What You Need


  • Cellphones with a QR app. For Androids, students can use this Get QR Droid. For iPhones, students can use QR Reader for iPhone. Other QR-reading apps also are fine.
  • Paper and pencils
Using QR Codes in Forensic Science


To use mobile technology and knowledge of forensic science to research a crime case.


Forensic science is the use of the tools of science to examine evidence, which can come from places ranging from an archaeological site to a crime scene. In criminal cases, forensic scientists gather evidence, such as hair, pieces of fabric, fingerprints, and blood, and analyze them by looking at the specimens under a microscope, comparing fingerprints to those found on databases of past offenders, and using face reconstruction software to determine what the perpetrator looks like. Because of the complexity of the subject matter, students should have some knowledge of forensics before working on this lesson.

In this lesson, students will be introduced to how technology can be used to solve crimes. They will gather evidence from Quick Response, or QR, codes. QR codes are multidimensional barcodes that can store different kinds of data, including images, text, and websites. QR codes have many different uses, including tracking industrial products, consumer advertising, and job recruitment. What's more, they can be created with a mobile phone application (app). In this lesson, students will use QR codes to solve a crime.

The lesson opens with a description of a crime that happened in the school—the school mascot has been stolen. Based on the information students have, they will develop an hypothesis about who committed the crime. After downloading a QR code app, students will work in groups to collect evidence, which has been placed around the classroom. The evidence will be embedded in QR codes. Students will work in their groups to decipher the codes, analyze the evidence, and try to figure out who stole the school mascot. 

After working with the evidence, each group will prepare a PowerPoint presentation for the class. Alternatively, students can put their findings into a QR code and have their classmates read their findings that way. After all the groups have made their presentations, the class will compare their ideas and make a class decision about who committed the crime. 

Planning Ahead

If you are unfamiliar with QR codes, you can read about them on these websites:

  • What Is a QR Code and Why Do You Need One?: This website gives some background about what QR codes are, how they are currently being used, and how they may be used in the future.
  • QR Code: This website provides in-depth information about QR codes, with discussions about how much information they can hold, how they are designed, and how they are stored.

If you are familiar with QR codes, go to the Evidence Found at the Crime Scene teacher sheet, which includes the QR codes needed for the lesson. There is a code for the fingerprint of the person who committed the crime, his/her hair sample, and a fabric sample left behind. Before the students do the activity, place each code around the classroom for students to find and decipher.


Your students probably know something about forensic science from television shows such as the CSI or Law and Order series, from movies, or from the Internet. Ask students if they find forensic science interesting. Ask: "What have you learned about forensic science from the media? What would you like to learn more about?" Accept all answers and encourage students to explain their answers.

Then tell students that scientists are always learning more about forensic science. Students should use the Using QR Codes in Forensic Science student esheet to go to the Hair Color Forensics audio clip to learn more about this topic. Alternatively, you can play the audio clip for the class. It explains how scientists can now determine hair color from a person's DNA. 

Discuss with students the ramifications of this discovery. Ask:

  • Why is this a breakthrough? 
    • (Scientists can use other evidence left at the crime scene, such as saliva, to figure out hair color.)
  • How do you think this new technique will help detectives solve crimes? 
    • (This discovery means that less physical evidence is needed to draw important conclusions about the criminal.)


During the lesson, students will use the tools of science to solve a crime that occurred in their school. They will be asked to think analytically, make inferences based on evidence, and draw conclusions.   

The following paragraphs explain the case and the suspects. This information is also on the Who Stole the School Mascot? student sheet, which you can hand out to students when you're ready to start the activity.

The Crime
The crime was identified when the principal noticed that the school mascot—a penguin—was missing from the shelf in his office where he keeps it. After conducting a thorough search of his office, his secretary's office, and all the rooms nearby, the principal concluded that the mascot had been stolen. He sent out a text-message alert to the teachers, asking for help in finding the penguin. He was especially concerned that it be located before the first football game of the season.

The teachers met with the principal to develop a list of suspects. They concluded that the perpetrator was probably one of these three people:

The football coach: He is considered the prime suspect. His motive may have been that he wanted to have the mascot available as a point of pride in the school and to encourage the players to do their best at the opening game. He is about 5'8", has brown hair, and often wears a blue jacket. According to school records, his fingerprint is a loop pattern. (The FBI characterizes fingerprints as a loop, arc, or whorl pattern. Check out Overview of Fingerprints for more information about fingerprints.)

The quarterback: He may have stolen the mascot to have as his own good luck charm. He is over 6' tall, has black hair, and wears a bright yellow sweater to practices. His fingerprint is also a loop.

The cheerleader: The cheerleader is good friends with the quarterback. She may have stolen the mascot to impress her friend. She is 5'4", has blonde hair, and often wears a dark green sweatshirt. Her fingerprint is an arc.

Divide the class into small groups of four students. Students should use the student esheet to look at resources that explain where to go to download a QR app for their phones or other mobile devices. Give students a few minutes to follow the directions and download the app.

Give students time in class to discuss the information they have about the three suspects. Based on what they know, ask them to develop a hypothesis about who stole the school mascot. Have them write down their hypotheses on the student sheet. In addition, ask students to write down on their sheets the kind of evidence they will look for.

Tell students that evidence, in the form of QR codes, is located throughout the classroom. Then give each group time to circulate throughout the class, locating the codes. Using their QR app, students can decipher the code and determine what evidence has been found.

Students will find this evidence:

After students have collected the evidence, have them meet in their groups to discuss their findings. Based on the evidence, can they deduce who stole the mascot? Remind students that all three pieces of evidence must match in order to identify the perpetrator of the crime. (Based on the evidence, students should conclude that the quarterback is the likely suspect who stole the mascot.) 


Students should prepare a presentation for the class using the evidence and information they recorded on the student sheet. Their presentation should state who they think commited the crime. The presentation can be done as a PowerPoint or as a QR code that the rest of the class must interpret.

You can use this rubric to help you evaluate the students' work in the lesson and their presentations:

  • 3 points: Students successfully downloaded the QR app, were able to use it to decipher the evidence, were able to interpret the evidence to determine who committed the crime, and were able to develop an interesting presentation explaining their results.
  • 2 points: Students successfully downloaded the QR app but had trouble using it to decipher the evidence. They could interpret some of the evidence to determine who committed the crime and were able to develop an interesting presentation explaining their results.
  • 1 point: Students had trouble downloading the QR app and using it to decipher the evidence. They also had trouble interpreting the evidence to determine who committed the crime and developing an interesting presentation explaining their results.

In evaluating students' work, consider these questions:

  • Have students mastered the technology? Were they able to download the QR app and use it to decipher QR codes?
  • Did students use critical thinking skills to analyze the evidence and figure out who committed the crime?
  • Did students show a greater understanding of the tools of forensic science? 


To give students more experience with forensic science, they can do the activities in these lessons on Science NetLinks:

Students also may enjoy working on the activities developed by the FBI on the FBI Kids Page.

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Lesson Details

Grades Themes Type Project 2061 Benchmarks National Science Standards