This download of Lesson 4 from a fun, interactive, 12-unit project-oriented forensic science course (each lesson lasting about an hour) is designed to engage and expose students to this truly fascinating area of science! Students in grades 4-5 are immersed in roles of crime scene investigators as they work together examining and analyzing evidence needed to solve the mystery of the broken cookie jar!
Using real laboratory techniques and materials, students create theories about the “crime” in a classroom, much as real detectives (and real scientists) use their powers of critical thinking to track down the thief. Along the way, they practice this critical thinking, acquire new vocabulary, explore careers in forensics, and become acquainted with scientific procedures and processes they will encounter in their future science electives. At its core, The Cookie Jar Mystery is designed to spark students’ interest in science.
Bringing the Mystery to Life
A crime has occurred in Mrs. Randall’s classroom! Her favorite cookie jar was broken and some of her homemade cookies were eaten. While breaking a cookie jar and snitching a few cookies are hardly serious crimes, they are nevertheless crimes that can be solved using a forensic science approach. Mrs. Randall turns this misfortune into opportunity and calls in a “Chief Crime Scene Investigator” (your course instructor) to lead her “forensics team” (your students) in how to use the tools of forensic science in analyzing clues left at the crime scene. Each student member of this team is a “Crime Scene Investigator” tasked with solving the mystery through scientific observation, sample examination, analysis, lab work, testing, interviews, and field work. To draw the students into the mystery, the instructor sets the stage by recounting Mrs. Randall’s intriguing tale. In advance, the instructor creates names for the four student suspects—names that students will find believable. These names replace “Suspects 1 – 4” used throughout the course materials. The suspects are three girls and one boy, and two of the girls are sisters. Having the instructor choose the names allows the course to be taught again and again, as this approach prevents incoming students from discovering prematurely who committed the crime.
Making the Most of Each Lesson
Instructors will find The Cookie Jar Mystery easy and fun to teach. Each lesson provides an activity that teaches a new but related aspect of scientific reasoning and a particular scientific process. None of the labs require special handling or complicated setups. After familiarizing themselves with the lesson, vocabulary, and intended outcome of the activity, instructors set up their classroom so that it is easy for students to work in groups. Clear guidance is provided in each lesson on how to organize the work areas with all the relevant materials at hand. Any necessary safety precautions specific to individual lessons are also provided.
Lesson 4 - Pull Some Strings: Fiber Analysis
Can scientific analysis of fibers help identify our thief? Students use pocket hand lenses to get up close and personal with fiber analysis, and learn to distinguish between class evidence and direct (conclusive) evidence.