Crime Scene Lab: The Trophy Case, a Crime Scene in One Period

Before you start: try it once yourself

Open mytekdev.com/try/crimescenelab?lesson=the-trophy-case&ref=fam-crimescenelab-1. A short guide opens over the app in a dark hallway you can turn and zoom: a trophy case on the back wall with a broken pane, glass under it, a trail of drops to the side door under the exit sign, lockers, a desk with a note, tape across the main door.

1. Photograph first. Camera, then press anywhere in the dark: photo 1, the whole room, and the lights come on. Press the trophy case to step up to it. Camera with close-up and with the scale, press the pane. The panel on the right reads the pane's state after every step.
2. Mark, glove, powder, tape. Marker on the pane. Gloves on. Powder on the pane: three prints come up, two from the hand that pushed the glass and one from the custodian who cleans it. Tape on one: lift 1, on a card. send lift 1 to the lab in the panel.
3. Make the mistake. Press The glass on the floor. Tweezers on a shard before any photo: the log says no photo in place, the strip counts 1 unphotographed, and the Case tab's chip for that shard carries the words. Now do the next shard the right way.
4. Print the answer key. Setup, then Print the answer key: the true story of this seed, whose prints are where, the pen, the shoe and the blood type. Keep it; it never appears in your child's copy.

The ideas, in plain words

A scene is documented before it is disturbed: the whole room, then each area closer, then each item close up with a scale in the shot so the photo can be measured. A numbered marker goes beside each item before it is collected, so the photo, the log and the bag all carry the same number. The log is the inventory; the chain of custody is the record of every hand the item passed through. These are the procedures in the published guides the app's teaching notes cite, and the app follows them exactly: a photo at close range with the scale is the only one the Lab can measure from.

Wet or biological evidence is air dried and packaged in paper, never plastic. The app plays this as a consequence: a swab in a plastic bag arrives at the lab spoiled. A latent print is the oil and sweat the skin leaves; powder brings it up on a smooth surface, and tape lifts it onto a card. Powder does nothing on paper, and the app says so if your child tries the note.

Common mistakes, each of which the app logs rather than prevents: picking up before photographing; a close-up without the scale; powdering with the gloves off, which adds your child's own print; brushing the powder twice, which smudges the print; a stain swabbed before it was photographed, which leaves nothing to measure.

Do it together

1. Open mytekdev.com/try/crimescenelab?lesson=the-trophy-case&ref=fam-crimescenelab-1 together. A short guide opens over the app in the dark hallway. Drag to turn it, scroll to move closer. Pick the camera and press the plan: the whole room, before anything is touched.

   You'll know it worked when: Your child can say why the camera comes before the tweezers.

2. Press the trophy case in the room. Camera again, close-up, with the scale, and press the broken pane. Then the Marker tool on the pane.

   If you get stuck: The scale chip only lights for a close-up. Pick close-up first.

   You'll know it worked when: The panel on the right says the pane has one photo close with the scale and marker 1.

3. Gloves on. Powder, and press the pane: three prints come up. Tape, and press one of them: it lifts onto a card. Press send lift in the panel.

   If you get stuck: If four prints came up, the gloves were off, and one of them is your child's own. The app says so.

   You'll know it worked when: The strip under the scene reads 1 lift.

4. Now the glass on the floor. Have your child pick up one shard with the Tweezers before photographing it, on purpose, and read what the log says.

   You'll know it worked when: Your child can say what the scene lost: there is no photo of where the shard lay, for good.

5. Process the floor and the desk the right way: photograph, mark, collect, paper bag, send. Then open the Evidence tab and read the chain of custody of any item.

   You'll know it worked when: Your child can read one item's chain aloud, in order.

Talk about it

Ask these while you work together. A child who has understood the lesson can answer them without help:

• Which of your photos can the lab measure from? What makes it the one?
• Read me the chain of custody of marker 2.
• Four prints came up on the pane. Whose is the fourth, and why is it there?
• Your swab is in plastic. What happens to it, and what should it have gone in?
• What does the strip's last number count, and why does it never hide?

Bring it into other subjects

• Math: measure two markers on the sketch from points A and B with the Measure tool, and check them against the printed answer key.
• Civics: find your state's rules on who may collect evidence at a scene and how long it is kept.
• English: write the chain of custody of one item as a paragraph, in order, with no numbers.
• Computer science: write the steps a program would follow to decide whether an item was photographed before it was picked up, from the app's log.

Quick check

Name: ______________________________

1. The photo the lab can measure from is: (A) the whole room (B) a midrange shot of the case (C) a close-up with the scale in the shot

2. A shard was picked up before it was photographed. The app says: (A) nothing (B) no photo in place, for good (C) take the photo now and it is fine

3. Name the two things that go beside an item before it is picked up, and say what each one is for.

Answers