Student Investigations — Summary Table¶
This is the teacher's planning view of every Student Investigation. Click any column header to sort (click again to reverse). Use it to build a term plan around your budget, your available lab space, and your safety comfort level.
- Type — Hands-on Physical (a real bench lab), Pure Virtual (stories + MicroSims, no consumables), or Hybrid (a physical step plus a virtual step that simulates an expensive instrument).
- Cost — approximate consumable cost per group (shared equipment such as microscopes and laptops is assumed on hand). "Free" means no consumables.
- Risk — the chance that a student or lab equipment could be harmed, rated Low / Med / High. See the rating basis below.
28 investigations: 9 Hands-on Physical · 8 Pure Virtual · 11 Hybrid.
| Investigation⇅ | Type⇅ | Cost⇅ | Risk⇅ | Description |
|---|---|---|---|---|
| Locard's Silent Witness | Hands-on Physical | $18 | Low | Prove every contact leaves a trace by documenting two-way fiber and glitter transfer between surfaces. |
| Map the Scene — Triangulation | Hands-on Physical | $12 | Low | Produce a scaled crime-scene sketch by triangulation, then prove it by reconstruction. |
| The Dusting Detective | Hands-on Physical | $22 | Low | Develop latent fingerprints with powder and match them to a suspect exemplar. (Super-glue fuming is a teacher demo only.) |
| Cold Case — AFIS Classification | Pure Virtual | Free | Low | Classify a latent print and search a suspect database the way AFIS does. |
| Human or Beast? | Hybrid | $15 | Low | Measure hair under a microscope and compute the medullary index to sort human from animal. |
| Fiber Under Fire | Hands-on Physical | $20 | High | Identify unknown fibers by burn behavior and solubility using a dichotomous key. Open flame plus acetone — ventilation and goggles required. |
| The Broken Window | Hybrid | $16 | Med | Use the Becke line to compare glass fragments to a source window. Handling sharp glass chips. |
| Which Blow Came First? | Hybrid | $8 | Low | Sequence impacts on fractured glass using the 3R rule. |
| Soil Signatures | Hands-on Physical | $18 | Low | Match boot soil to a location by color, pH, and particle layering. |
| Is It Blood? | Hands-on Physical | $14 | Med | Run a presumptive blood test and reason about false positives. Uses hydrogen peroxide and phenolphthalein — goggles and gloves. |
| Type the Blood | Hands-on Physical | $35 | Low | Determine ABO/Rh type from agglutination to include or exclude suspects. Simulated blood — no biohazard. |
| Reading the Spatter | Hybrid | $12 | Low | Measure stains and calculate the impact angle from width and length. Washable simulated blood. |
| Stringing the Scene | Hybrid | $16 | Low | Reconstruct the 3D area of origin of a bloodstain pattern. |
| From Strawberry to Suspect | Hybrid | $10 | Low | Extract real DNA, then match a simulated STR profile to a suspect. Food-safe household materials. |
| Beat the Odds | Pure Virtual | Free | Low | Apply the product rule to compute a random match probability for a jury. |
| Color-Test Chemistry | Hybrid | $12 | Med | Screen safe unknown powders with color spot tests, then confirm by simulated GC-MS. Indicator chemistry and iodine — goggles and gloves. |
| Point of Origin | Pure Virtual | Free | Low | Read V-patterns and char to locate a fire's origin and spot arson — no real fire. |
| Bones Tell Tales | Hybrid | $25 | Low | Estimate biological sex and stature from skeletal measurements. |
| The Bug Clock | Hybrid | $10 | Low | Estimate time of death from larval length and accumulated degree hours. (Optional insect rearing raises handling and odor considerations.) |
| Toolmarks & Impressions | Hands-on Physical | $15 | Low | Match a pry mark to a tool by class and individual characteristics. |
| Which Pen Wrote the Note? | Hands-on Physical | $10 | Low | Separate ink pigments by chromatography to identify the pen used. |
| Forged or Genuine? | Hybrid | $6 | Low | Compare questioned and known handwriting to judge authenticity. |
| Hash It Out | Hybrid | Free | Low | Compute and compare cryptographic hashes to detect tampering of digital evidence. |
| Metadata Detective | Pure Virtual | Free | Low | Use EXIF timestamps and GPS to break a suspect's alibi. |
| Locate the Phone | Pure Virtual | Free | Low | Triangulate a phone from cell-tower records and state the uncertainty. |
| Mapping the Conspiracy | Pure Virtual | Free | Low | Build a network graph and find the ringleader using centrality. |
| Reconstructing the Debris Field | Pure Virtual | Free | Low | Classify a crash debris field and build a probable-cause hypothesis. |
| Face in the Crowd | Pure Virtual | Free | Low | Trace a facial-recognition pipeline and evaluate its bias and admissibility. |
How Risk Is Rated¶
The risk rating reflects the chance that a student or lab equipment could be harmed during the student-performed portion of the lab, assuming normal classroom PPE and supervision.
| Rating | Meaning | Examples in this book |
|---|---|---|
| Low | No hazardous chemicals, flame, or sharps in the student steps. Everyday or simulated materials. | Tape lifts, chromatography, simulated blood typing, all Pure Virtual labs. |
| Med | Mild chemical irritants or sharp materials that need goggles, gloves, and close supervision. | Kastle-Meyer (hydrogen peroxide), color spot tests (iodine), handling glass chips. |
| High | Open flame and/or flammable solvent — requires a fume hood or strong ventilation and one-station-at-a-time supervision. | Fiber Under Fire (burn test + acetone). |
Always pair with your district's lab-safety policy
These ratings are a planning aid, not a substitute for your own risk assessment. No investigation uses real blood, real controlled substances, or unsupervised flame — every "blood," "drug," and "accelerant" in the book is a safe simulant. Confirm PPE, ventilation, and disposal against your local requirements before running any physical lab.