Ethics of the scene
Do now
Debate whether investigators should be allowed to alter a scene to collect evidence, and defend your view.
- Hand in
- Written CER (3-5 sentences) taking a side on whether investigators should disturb a scene to collect evidence, with a chain-of-custody reference in the reasoning.
- Where
- Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
You get two school days for every day you were absent, so this deadline moves with you.
You spot a single fiber on a body, but lifting it will scatter the dust pattern underneath. Do you grab the fiber or leave the pattern intact, and how do you defend that choice?
Debate whether investigators should be allowed to alter a scene to collect evidence, and defend your view.
- • I can connect scene handling to chain-of-custody integrity.
- • I can defend a claim with a reason and an example.
- Name one thing you could learn by picking up an object at a scene, and one thing you could lose by picking it up.
- Why would a court throw out evidence even if everyone agrees the object came from the scene?
- 1Read the prompt: When does collecting evidence cross into destroying it?
- 2List one cost and one benefit of disturbing a scene to gather .
- 3Choose a side: preserve untouched vs. collect aggressively.
- 4Argue your claim in your group with one reason grounded in .
- 5Post a written CER stating your position and one piece of supporting evidence.
What did this day actually feel like?
Ethics of the scene
ETHICS DAY The question today: when does collecting evidence cross the line into destroying it? To get a fiber off a carpet you have to move the carpet. To swab a surface you have to touch it. Every piece of evidence you take changes the scene you took it from.
I argued for collecting aggressively, because evidence you did not collect is evidence you do not have. The other side argued for preserving the scene untouched, because once you have contaminated it you can never go back and the defense will say so. Neither side wins cleanly, which I am starting to notice is true of every Monday question.
Turned in: CER → Claim Evidence Reasoning folder
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
The same day, drawn.
No school Monday, so the ethics debate moved. When does collecting evidence cross into destroying it? To lift a fiber you have to move the carpet.
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
🛠 Get unstuck · pick your level
🔑 Today's words · 5
Tap a word in the lesson for a plain meaning and one example. Recycled into next week's Do-Now.
Do the work · 80-minute blockfirst 5 min = hook▸
💡 Big idea: How you handle a scene determines whether its evidence can be trusted, because or a broken record makes even genuine evidence inadmissible.
- 0:00Hook: short description of a famous case where scene threw out key evidence
- 0:08Introduce chain-of-custody concept; students define it in their own words
- 0:18Read the ethics prompt; list one cost and one benefit of disturbing a scene
- 0:30Small-group debate: pick a side, argue with one reason grounded in
- 0:52Individual CER writing: position, one piece of evidence, one reasoning sentence
- 1:10Share two CERs; preview Tuesday scene-documentation content
- • Imagine you are the first person on the scene of a suspicious death. What is the first thing you do? If you touch anything before documenting it, you may just have destroyed the best evidence.
- • Today's question is a genuine ethical dilemma that real investigators face: when does collecting evidence cross the line into destroying it?
- • The legal concept of means that every piece of evidence has a paper trail from the moment it is found. Break the chain and a lawyer can throw the evidence out entirely.
- • Your job today is to pick a side and defend it with reasoning. There is no easy answer, and that is the point.
- • is the documented record showing who handled evidence, when, and how, from collection to courtroom.
- • Disturbing a scene without documentation can contaminate or destroy , rendering it inadmissible.
- • Every collection decision involves a tradeoff between preserving context and obtaining a sample.
Unit 1.1 Investigating the Scene: Forensic scene documentation, evidence log, crime-scene sketch, trace evidence, biometric data. · Ethics of the scene
Day 1 of this lesson. Open this exact section in myPLTW (find it in Clever, Microsoft sign-in), then do the work below.
Do this: Log in to myPLTW and open the Lesson 1.1 Investigating the Scene unit. Read the unit overview so you understand the case and chain-of-custody framework before Tuesday.
Mark the Lesson 1.1 overview reading complete in myPLTW.
You finished the course launch last week. Today starts Lesson 1.1. The overview reading should be done by the end of this block.
myPLTW progress screenshot showing the Lesson 1.1 overview task marked complete.
The official PLTW activity stays inside myPLTW. If myPLTW will not open, use F1 and E1-E3 on this page to complete today's local evidence decision, then make up the official activity when access returns. Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Check things off as you work, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible through the submission route shown below.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
Unit 1.1 Investigating the Scene: Forensic scene documentation, evidence log, crime-scene sketch, trace evidence, biometric data. · Ethics of the scene
Log in to myPLTW and open the Lesson 1.1 Investigating the Scene unit. Read the unit overview so you understand the case and chain-of-custody framework before Tuesday.
You finished the course launch last week. Today starts Lesson 1.1. The overview reading should be done by the end of this block.
This is how Mr. Mendoza sees the class keeping pace with PLTW. Be honest, it only helps if it is accurate.
🎯 Debate whether investigators should be allowed to alter a scene to collect evidence, and defend your view.
- Read the prompt: When does collecting evidence cross into destroying it?
- List one cost and one benefit of disturbing a scene to gather .
- Choose a side: preserve untouched vs. collect aggressively.
- Argue your claim in your group with one reason grounded in .
- Post a written CER stating your position and one piece of supporting evidence.
CER: Written CER (3-5 sentences) taking a side on whether investigators should disturb a scene to collect evidence, with a chain-of-custody reference in the reasoning.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Use the checklist just below and upload by 11:29 PM for full credit. Absent with an excused absence? You get two school days for every day you were absent, so this deadline moves with you.
| Task | Who |
|---|---|
| Read the prompt: When does collecting evidence cross into destroying it? | _______ |
| List one cost and one benefit of disturbing a scene to gather . | _______ |
| Choose a side: preserve untouched vs. collect aggressively. | _______ |
| Argue your claim in your group with one reason grounded in . | _______ |
| Post a written CER stating your position and one piece of supporting evidence. | _______ |
Working solo? Put your own name in "Who" for every row.
- I can connect scene handling to chain-of-custody integrity.
- I can defend a claim with a reason and an example.
- 1Do thisDebate whether investigators should be allowed to alter a scene to collect evidence, and defend your view.
- 2Use this resource
- 3Submit thisCER: Written CER (3-5 sentences) taking a side on whether investigators should disturb a scene to collect evidence, with a chain-of-custody reference in the reasoning.
- 4Submit it here
- 1Open the drop folder.
- 2Sign in with your district Microsoft account, not a personal one.
- 3Upload the file, named Lastname_Firstname__Assignment Title.
- 4Your own upload panel says Uploaded with a green check: that is your receipt.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Principles of Biomedical Technology (Principles of Biomedical Science) › Unit 1.1 Investigating the Scene: Forensic scene documentation, evidence log, crime-scene sketch, trace evidence, biometric data. › CEROpen the drop folder
Learn it · deck, reading, and vocabulary▸
The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.
Generated from this lesson's canonical data with a red-team citation check.
and a well-labeled graph turn raw measurements into evidence a scientist can defend.
How you handle a scene determines whether its evidence can be trusted, because or a broken record makes even genuine evidence inadmissible.
A detective board holds observations, possible explanations, and one next question.
- Which notes are direct observations?
- Which notes are explanations?
- What new evidence would separate the explanations?
Keep observations separate from explanations, then collect the evidence that can distinguish the options.
Biomedical investigations use controlled procedures and validated measurements, not intuition alone.
- • Board notes map to E1-E3.
- • Possible explanations map to the decision options.
- • The next question maps to the evidence-based action.
Driving question: You spot a single fiber on a body, but lifting it will scatter the dust pattern underneath. Do you grab the fiber or leave the pattern intact, and how do you defend that choice?
What you already know: and a well-labeled graph turn raw measurements into evidence a scientist can defend.
New idea: How you handle a scene determines whether its evidence can be trusted, because or a broken record makes even genuine evidence inadmissible.
Visual or model: F1. F1. A lesson illustration or teaching diagram for Ethics of the scene. Use it with E1-E3; it is a model or context image, not experimental or patient data. What to notice: Trace the labeled observation or evidence sequence before choosing an explanation.
- Observe or measure the relevant feature in Ethics of the scene.
- Organize the observation with a stable evidence ID.
- Apply this rule: Keep observations separate from explanations, then collect the evidence that can distinguish the options.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: You spot a single fiber on a body, but lifting it will scatter the dust pattern underneath. Do you grab the fiber or leave the pattern intact, and how do you defend that choice?
What the evidence supports: E1-E3 and F1 support the daily take-home when the response meets the stated success criteria.
What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.
- • : Relating to the use of science to examine evidence and answer questions in legal investigations, such as identifying a person or cause of harm.
- • : Tiny physical materials, such as hair, fibers, or soil, transferred during contact at a scene, used to link people, places, and objects in an investigation.
- • biometric: A measurable physical or behavioral trait, such as a fingerprint, iris pattern, or heart rate, used to identify a person or track health.
- • observation: Information gathered directly through the senses or instruments, recording what actually happens without yet interpreting it.
- • inference: A conclusion drawn by reasoning from evidence and observations rather than from direct, firsthand measurement.
- • : The documented record of who handled a piece of evidence, when, and where, proving it was never lost, swapped, or tampered with.
- • : A reference sample treated like the others but without the variable being tested, giving a baseline to compare experimental results against.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice.
Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.
is the documented record showing who handled evidence, when, and how, from collection to courtroom.
Limit: E1 supplies context or an observation; it does not by itself establish the explanation.
How you handle a scene determines whether its evidence can be trusted, because or a broken record makes even genuine evidence inadmissible.
Limit: E2 is a teaching statement or comparison and must be checked against the task evidence.
I can connect scene handling to chain-of-custody integrity.
Limit: E3 supports only the result or product criterion named here; it cannot justify a broader clinical or causal claim.
PLTW-PBT-2026-09-08 · Simulated classroom evidence scenario
Your role: biomedical investigator
Decision: Your team must decide what the evidence from Ethics of the scene supports before submitting the claim-evidence-reasoning response named on the lesson page.
- • Choose the strongest supported explanation.
- • Choose the next evidence to collect.
- • Hold the decision because the evidence is insufficient.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the claim-evidence-reasoning response.
Claim ceiling: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about Ethics of the scene. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
Reason for review: Your team must decide what the evidence from Ethics of the scene supports before submitting the claim-evidence-reasoning response named on the lesson page.
Context: How a scene is handled decides whether anything found there can ever be trusted, because evidence with a broken record is worth nothing in a courtroom.
- • T1: Read the prompt: When does collecting evidence cross into destroying it?
- • T2: List one cost and one benefit of disturbing a scene to gather .
- • T3: Choose a side: preserve untouched vs. collect aggressively.
- • T4: Argue your claim in your group with one reason grounded in .
- • T5: Post a written CER stating your position and one piece of supporting evidence.
- • E1: is the documented record showing who handled evidence, when, and how, from collection to courtroom.
- • E2: How you handle a scene determines whether its evidence can be trusted, because or a broken record makes even genuine evidence inadmissible.
- • E3: I can connect scene handling to chain-of-custody integrity.
Measurements: No patient measurement is supplied unless it appears explicitly in E1-E3 or F1. Do not invent a value.
Figure finding: Teaching diagram for Ethics of the scene. Trace the labeled observation or evidence sequence before choosing an explanation. This is a teaching model, not patient or experimental data.
Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.
Students often think Students think as long as an item truly came from the scene, it counts as evidence no matter how it was collected.. The trap: It does not count unless the handling is documented, because a court has no way to tell real evidence from planted or contaminated evidence except by the record of who touched it and when. No record means no case.
Claim: When investigators seize a phone, they should copy it and search only the copy, even though making a forensic image takes extra time before anyone can look at the data.\nEvidence: Simply turning on a seized phone and swiping through it changes the device. Opening a message marks it as read, and new activity can overwrite deleted files or update timestamps, so the original state of the data is lost the moment someone browses it directly.\nReasoning: For digital evidence to hold up, an investigator has to show the court that what was presented is exactly what was on the device when it was seized, with nothing altered. Creating a verified image first, then searching the copy, keeps the original untouched and documented. If instead someone browses the live phone and changes it, a defense can argue the files were modified or added after seizure, and the judge may throw the evidence out. Copying before searching protects the data so it can actually be used in court.
This model shows the level of evidence and organization needed to complete: A written claim-evidence-reasoning paragraph on a parallel evidence-integrity case (imaging a seized phone before searching it), modeling the CER format and depth without answering today's scene-disturbance prompt.
- Write one defensible claim.
- Choose specific evidence that supports the claim.
- Explain the scientific rule that connects the evidence to the claim.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Also due today: Post your CER to the discussion board or hand in the written copy before leaving.
- CER:
- Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
- SOP:
- Standard Operating Procedure, the exact steps to follow (especially in a lab).
- Tracker:
- Your PLTW progress log where you record completed evidence.
- myPLTW:
- The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
Tap the speaker to hear a term. Add two of these to your notebook glossary with a definition and an example in your own words.
Pick just 2 or 3 words from today and make them yours: write what each one means in your own words, name the context clue or evidence that helped, then give one example from what you actually did in Ethics of the scene. Try your own words first; the glossary is there if you get stuck. This is voluntary and counts as extra credit, so keep it short.
Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.
Hand-picked readings and interactives for this lesson, from authoritative open organizations and PLTW's own public course outline.
Check yourself · commit, then reveal▸
Claim ceiling for this check: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about Ethics of the scene. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
An officer photographs a scene, then picks up a bloody shirt with bare hands and puts it in an unlabeled bag. Give two separate reasons this evidence may be thrown out.
Write an answer and pick a confidence to unlock the key.
Fast retrieval with instant answers, not the commit-then-reveal check above. Try each from memory first: write what you remember about the earlier units, then check yourself here.
Go further and get help▸
What today's skills lead to. These are real health-science careers this course builds toward. Tap one to see, on the US Department of Labor's O*NET site, what the job actually involves, what it pays, and how fast it is growing.
Watch the recorded scene-ethics prompt and post your written CER taking a side on whether disturbing a scene is justified.
John Carroll Philosophy for ChildrenThen submit your CER. Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Class still runs. Complete the online activity above (it's self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
Khan Academy: using the microscope (Cell biology)- CompleteEvery required part of the artifact is present, nothing left blank.
- AccurateThe science and the data are correct and match the evidence.
- Scientific reasoningYou explain your claim with evidence and reasoning (CER), not just an answer.
- Professional communicationClear, organized, labeled, and written the way a clinician or scientist would.
- SubmittedTurned in the right way, on the class site or handed to Mr. Mendoza in class, and confirmed. Not in Schoology: that is where the report-card grade appears later.