We all know the importance of writing scientific explanations through CER (Claim Evidence Reasoning). However, this can be difficult, and my students often get confused between the evidence and reasoning part. They will write many reasonings to support their claims but leave out the evidence part, or they will have lots of evidence with no reasoning as to why that evidence supports their claim.

To help my students out when I first introduce Claim, Evidence, Reasoning, I tap into their love of Crime Scene Investigations (CSI). My students love watching shows where they have to figure out what happened and solve the case. These shows lend themselves very well to helping students understand the difference between evidence and reasoning. So I created a case mystery using CSI and a little inspiration from the game of Clue that has them using their observation and analysis skills to find out what happened.

The students are given a journal to take notes and write down their observations from the crime scene, the police report, and the forensic evidence. They take notes on what they already know and what information they will need to research because they might not know what a name means or what something is used for. The forensic evidence includes fingerprint analysis, DNA identification, blood analysis, autopsy report, and chemical analysis to identify if he has any known drugs or alcohol in his system.

As they look at the evidence, they start to formulate what happened to their claim. They have discussions with students in their group, and they analyze the information and decide which information is important and which information is not necessary.

They then research any information or words that they might not know. For example, they need to look up the prescription drug found on the table to determine what it is used for. They might have to look up the word Bovine to determine how that might have shown up in blood or DNA analysis.

The students have a great time discussing what happened and if foul play was part of it or the person just died of natural causes. We then talk about how the evidence they use to support their claim needs to come from the actual police report, crime scene, and forensic reports. Their reasoning explains their claim and why the evidence supports it. We also discuss reasonable doubt and why specific DNA or fingerprints might naturally occur at the crime scene.

In the end, they all conclude that the person died of a heart attack and blood loss from hitting their head, and they can support their claim with evidence from the scene and their knowledge of what the medication is used for.

You can find this Crime Scene Investigation CER activity here: https://adventuresinistem.com/CSI for CER