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Notes for the Instructor

In this lesson, students will practice being part of an evidence response team. They will locate evidence and clues, determine which ones need to be preserved against weather and time, and map evidence at a crime scene.

The underlying principle in crime scene investigation, the idea that “every contact leaves a trace,” belongs to Edmond Locard who created the first forensic lab in 1910 in Lyon, France. Today, the Federal Bureau of Investigation has a division called the Evidence Response Team. This team consists of a team leader, a photographer, a sketch preparer, an evidence custodian, and an evidence collector, among others. During their training, the agents focus on evidence collection and preservation, crime scene investigation, and the use of search warrants.

Securing the scene is necessary to make sure the evidence is not compromised in any way. Taking photographs is the best way to document the scene; videotaped footage is often used as well. If neither is possible, then sketches can be made. Searching for evidence can be difficult since the investigator may not know what may be a clue or evidence. To locate clues, a search must be conducted. Outside, officers walk in a line to search large areas. Inside, rooms are listed and searched in an orderly fashion. Once clues are located, those subject to damage by weather or time must be studied first.

Although photographs are usually taken, crime scene sketches are also created. There are several ways to plot evidence on a sketch. The most accurate method is triangulation. Triangulation involves creating a triangle with one point being the evidence and two fixed points chosen in the room or area. Fixed points can be windows, doors, corners of rooms/ buildings or anything else that is stationary and unable to move. In this activity, students will use the triangulation method to determine the distance of evidence from fixed points.

The activities in this lesson address Next Generation Science Standards practices of Asking Questions and Defining Problems, Planning and Carrying Out Investigations, and Engaging in Argument from Evidence. In addition, they address Common Core State Standards CCSS.ELA-Literacy. CCRA. SL.1, CCSS.ELA-Literacy.CCRA.SL.2, and CCSS. Math.Content.3.MD.B.4. See the Standards Matrix included in the appendix for more detailed information.