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Student Introduction






The Cookie Jar Mystery


Mrs. Randall is a science teacher. She enjoys baking chocolate chip cookies and sharing them with her students. One morning when Mrs. Randall entered her classroom, she found her favorite cookie jar in pieces on the floor. She had baked cookies the day before, but now only a few pieces of broken cookies were left on the floor, next to the pieces of the cookie jar.

Mrs. Randall loves to teach, and she loves to use science to solve mysteries and answer questions. She decided to use “forensic science” to solve this mystery of the broken cookie jar, and she got her students to help her. Now she wants you to use forensic science to solve the mystery, too!

So what is forensic science? Forensic science is science that relates to the law. The word “forensic” means anything related to the handing out, or administration, of justice. You will look at the clues left in Mrs. Randall’s classroom and use forensic science to decide who broke the cookie jar and ate the missing cookies.

On the morning that Mrs. Randall discovered the broken cookie jar, she entered her classroom from the door at the back of the room. She set some books and papers on the work counter, then she checked on the plants her students were growing on the windowsills. It was when Mrs. Randall got to the front of the classroom that she saw her favorite cookie jar on the floor in pieces. The door to the storage cabinet where Mrs. Randall usually kept the cookie jar was open, and pieces of cookies were scattered between the cabinet and Mrs. Randall’s desk. It was a mess.

Mrs. Randall stopped by the front work table while she thought about what she should do. She knew it was important not to touch anything that could give clues about who had broken the cookie jar. But she had to get ready for her class to arrive. She decided to look at everything carefully and take notes about what she found. She took a digital photo of the crime scene. Then she put anything that looked unusual or out of place into a box so she could look at it all carefully later. She also made a map that showed the layout of the “crime scene.”

Here is what she found on the floor: fragments of the broken cookie jar, pieces of cookies, lots of crumbs, and an old science test. A couple of pieces of broken cookie jar looked as if they had something on them. Mrs. Randall swept the floor and looked at everything in the dustpan carefully. She noticed some hair and maybe some threads or tiny, tiny pieces of material. She put it all in plastic bags to analyze later.

When Mrs. Randall went to her desk with the box, she found something else: a note and a half-eaten cookie! She put the note and the half-eaten cookie in the box, too. She wondered, who could have done this? Later, she decided it had to be one of four suspects, students who had the opportunity to be in her classroom while she was out. The suspects are:


#1_____________________________________ (male);

#2_____________________________________ (female);

#3_____________________________________ (female); and

#4_____________________________________ (female, sister of #3).


You will be a Crime Scene Investigator to help solve this mystery. Your instructor will be your Chief. Are you ready to solve this mystery?