If the Shoe Fits Activity Version

Display slides 2–4 to introduce the essential question and learning objectives. Continue to slide 5 and present the crime scene scenario that sets up the first activity.

Go to slide 6–7 and define impression evidence and share with students how three-dimensional impressions can be collected via dental stone. Tell students that they will be collecting their own dental stone impressions next.

Group students into groups of 2–3 and provide each student with the Impressions Investigation handout. Have students use the “Dental Stone Casting - 3D Impression” section of the handout as you review the investigation procedures for casting the impression. Display slide 8 to show an abbreviated version of the casting instructions.

Go to slide 9 and give the classroom-specific instructions for how they will proceed with the activity by working through steps 1–5 on the Impressions Investigation handout. Have students complete the dental stone castings and set them aside to dry.

While the casts are drying, display slides 10–13. These slides provide a brief overview of categories of impression evidence, and focus specifically on three-dimensional impressions. After covering the content, tell students that they will focus specifically on shoe prints in this lesson, but the techniques for documenting other kinds of impression evidence are similar.

Continue to slides 14–15 to review with students how to document three-dimensional impression evidence. Emphasize to students the importance of including a measuring device for scale to ensure that the evidence can be measured accurately. Point out that measurements should be triangulated from two fixed points. Next, go to slides 16–19 to show examples of photographs of the same impression taken from different flash angles.

Display slide 20 and provide the student time to finish steps 6 and 7 on the Impressions Investigation handout.

Tell students they will be analyzing their three-dimensional impressions and comparing them to the known shoe to determine if any of the impressions match. Note that only one group’s impression will match the known shoe.

Next, go to slide 21. Students will use a modified version of the I Think, We Think strategy. For the “I Think,” provide a sheet of paper and have students in small groups generate a list of shoe features an investigator might look at in order to determine whether an impression matches a known shoe. Then have the class come together to share out those ideas as the “We Think.”

Go to slides 22–27 and review considerations, class characteristics, individual characteristics, and wear. Slide 25 has a zoomed-in comparison of an impression and matching shoe, with slide notes describing the individual characteristics numbered on the image. Next, distribute the Lab Data and Questions handout and display slide 28 to go over the data table format. In their investigation groups, have students document their castings with a sketch and measurements, and record individual and class characteristics. While students work on this, pass the known shoe around the room and have students record the same information for it as well.

After completing their side-by-side comparison, have students answer the question beneath the Known Shoe - Outsole table:

• Were you able to make a positive identification of the suspect’s shoe from your dental stone impression?

• How did the data help you reach your conclusion?

Have the group with the matching impression explain their reasoning to the group.

Students now practice making, collecting, and analyzing two-dimensional impressions and matching prints to their peers’ shoes.

Go to slides 29–31 and introduce two-dimensional impressions and documentation of evidence. Slide 31 has example photos of oblique lighting for reference.

Return to the lab instructions and review with students the investigation procedures under the 2D Inked Impression heading. Slide 32 has an abbreviated version of these instructions that you can display as well. Have each student make their impression. Collect finished impressions and label each with a unique letter.

Students should record characteristic data about their known shoe on their data sheet, as with the three-dimensional impressions. After students have completed their impressions, redistribute the prints or have them take a known shoe.

Go to slide 33 and give students classroom-specific instructions for how they should proceed with the activity. Have them document measurements and characteristics on their data sheet (or inked impression) as they did for the three-dimensional impressions. Using the data, have students circulate the room to match the two-dimensional impressions and shoes.

After completing their comparisons, have students answer the questions beneath the Inked Impression table:

• Were you able to make a positive identification between a print and a shoe?

• How did the data help you reach your conclusion?

Bring the group back together after they have successfully matched their prints and shoes and ask them to answer the lab questions at the end of the data sheet. This can be done individually or collaboratively. Next, use slides 34–37 to open up a discussion with the students about how they used evidence to draw their conclusions about whether an impression matched a shoe (i.e., what characteristics they used). The goal is for students to come away understanding some of the strengths and challenges associated with collecting and analyzing impression evidence, and using it for identifying suspects.

Conclude the activity by going to slide 38 and having students complete an I Used to Think…But Now I Know reflection about forensic impression evidence. Provide each student with a sheet of notebook paper. Have them create a table with two columns and label the left side with “I Used to Think” and the right side with “But Now I Know”.