Crime Busters

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Course content was made from Forensics lead faculty, including:
Harshit Kolisetty, ScioVirtual executive director and molecular biology student at UC Berkeley. Harshit has taught forensics numerous times at ScioVirtual and will be teaching Chemistry Lab this summer.
Ankita Kundu, NJ Science Olympiad gold medalist from WW-P North. Ankita has taught forensics and managed chemistry courses at ScioVirtual.
Victoria Li, NJ Science Olympiad gold medalist from WW-P North. Victoria has taught Crime Busters and Disease Detectives at ScioVirtual.

Welcome to Division B Crime Busters, the illegitimate child of Division C Forensics.

At first glance, Crime Busters may seem like a simple test of memorization of identifying mystery samples and their potential uses at the crime scene. However, one must understand the underlying chemistry and biology concepts in order to succeed. On top of the overall crime scene that students need to solve for the event, Crime Busters tests often contain tons of trivia questions that make up a significant portion of the point total. More than anything, be ready to adapt: test writers are creative with their test styles so you’ll need both logical thinking and your knowledge to do well.

In that sense, the event is easy to get into, but difficult to progress higher past that point. Every single test will be structured around a crime case: Division B will usually be some sort of theft or vandalism, but I’ve found that Division C is just full of murders. Therefore, the first thing you should always do is skim through the crime scene and suspect descriptions and underline important information.

Crime Busters (when in-person) can be generally split into a lab portion and a test portion. The lab consists of powder, and sometimes liquid, identification. It would definitely be helpful to have a comprehensive chart of how each substance reacts and behaves to aid you during the lab. Do not just have a flowchart in which some of the substances will be identified by process of elimination (i.e identifying a substance because it reacted with nothing)— you’re going to be screwed for certain competitions in which not all reactants will be available (i.e. iodine, hydrochloric acid, etc.). Especially since a lot of competitions have been virtual lately, so you’ll just be given descriptions instead, which often will not include things like visual and smell but have “mistakes” in the descriptions they offer. For example, if they give you a chart with 5 reactions for each powder and ask you to identify, 1-2 of the reactions will be incorrect and you’ll have to list out the mistakes as well.

*Ignore for virtual competitions* There are often other smaller labs throughout the room, usually chromatography. It takes a good 10-15 minutes for chromatography to develop, so if you notice your test having one, it’s a good idea to get one set up first. Chromatography itself is not hard but it’s easy to mess up. Make sure to:

  • Label each sample (with pencil) if there are multiple
  • Keep the sides of the beaker where you are performing the chromatography dry
  • Try to keep an eye on the clock → letting a chromatography sit there for 50 minutes isn’t a good idea
  • Keep an eye on the beaker → don’t let paper fall over (it may be a good idea to just skewer a pencil or stick through the paper and rest it on top of the beaker)
  • Listen carefully to the instructions your proctors give. Stations may be set up for each team or as communal ones for every team. Pay attention to which stations are available and where they are. Because sometimes if you ask your proctor where the chromatography paper is, they’ll just answer with “Everything you need is in this room.”

Overall just know which partner is going to do which section (the person who does lab will likely finish early and help with sections of the test). Keep an eye on the clock so you’ll have time to discuss, choose a suspect, and write out your reasoning. Also try to keep a mental checklist on who the most likely perpetrator is based on your evidence so you won’t have to go back later.

Here are the steps one can take to go from an absolute beginner to the next Edmond Locard:

  1. Learn the basic concepts necessary to be able to identify compounds
  2. Thoroughly study the scientific principles further
  3. Compile common uses for each potential sample
  4. Learn advanced trivia
  5. PRACTICE!!!

Breakdown of Crime Busters:

  • Qualitative Analysis
    • Powders
    • Liquids
    • Metals
  • Chromatography
  • Polymer Testing
    • Cloth Fibers
    • Hairs
    • Plastics
  • Physical Analysis
    • Fingerprints
    • Biological and Chemical Tests
    • Miscellaneous evidence (e.g. soil, splatters, shoeprints)
Taken directly from the official Science Olympiad Rules Manual
Taken directly from the official Science Olympiad Rules Manual
  • Final Written Analysis

General Tips:

When first reading the crime scene and suspect details, make sure to highlight important information that could potentially indicate the presence of a certain chemical/fiber/sample. Thankfully, test writers often utilize the same uses for certain chemicals across tests.

Crime Busters tests are often big time crunches. Unlike other events where one can still do well by not answering all the questions, in Crime Busters, you will often need all the evidence you can get in order to deduce the most probable perpetrator of the crime scene so you’ll need to be able to move from section to another as quickly as possible. Writing an accurate final analysis can often be worth a third of the entire test itself so it might be a good idea to save all the trivia for the end (despite how tempting they can be to answer).

Because of the pace that the test requires, it’s a good idea to split up topics with your partner, as early as when you first find out who your partner for the next competition is. Splitting up topics doesn’t mean you can avoid learning certain topics completely, it just means that one person is more comfortable with and has more interest in those topics; that can be determined by doing a lot of practice tests beforehand. Splitting up topics like this also means that you need to have complete faith in your partner’s capabilities. Here’s how I used to split up topics with my partners:

Partner 1: Qualitative analysis, Chromatography, Fingerprints, Biological tests, Trivia

Partner 2: Cloth fibers, Hairs, Plastics, Physical analysis, Final analysis

Guides to analyzing evidence types

Crime Busters Scioly Wiki is always a good place to start with learning the basic info and adding it all to a cheatsheet. The rest of the info you can find online → make sure to get a detailed list of uses for all substances (powders/liquids/fibers/plastics). Sometimes the suspect description will give you the use for a substance instead of the actual name: for example, a suspect that wears glasses can match with polycarbonate.

In my opinion, the best way to study for CB is to get hands-on practice, whether that’s taking an entire mock test or doing some lab work. If you don't have the powders or liquids available, it’s easy to go onto YouTube and search for things like “Iodine and Cornstarch Reaction”.

For hairs and fibers, http://www.microlabgallery.com/hair.aspx is a good source with tons of pictures of all different types of hairs.

Qualitative Analysis

The slides with the chemicals tested in Division B Crime Busters have a red dot 🔴

Keep in mind that a flowchart might not be the best format for your cheatsheet; this activity is simply meant to engage you with the material.

Use the following for taking notes and reviewing your knowledge of the chemical properties of the various samples:

Learning Tip #1 Taking notes is a vital technique for studying as you physically interact with and interpret the material as you put information into your own words.
Learning Tip #2 Taking notes isn’t everything. In situations where application of the material is more important, you need to actively engage with the content and practice building connections between ideas. I feel that transforming content from one format to another is a great way to show comprehension of the material (ex: creating a flowchart to organize the various test results for qualitative analysis, creating a table to organize fiber characteristics)


Note: Make sure you know how the concept of differing polarities and attraction towards different chemicals plays a role in chromatography. Study up on molecular polarity for review.

Cloth Fibers

Use this to take notes on the physical qualities of fibers:

This document is helpful for practicing identifying fibers and plastics using two different test results each:



Note: A common trivia question that’s asked is what the two types of plastics are and how they differ. Make sure to review the processes of addition and condensation polymerization. The difference between thermoset and thermoplastic is also frequently asked.

Here’s some review and practice with identifying plastics:

The sliver test is rarely provided but it’s helpful for differentiating between thermoset and thermoplastic plastics. Thermoplastic plastics yield a smooth result while thermoset plastics yield a powdery result.

Physical Analysis

Here are tons of review and practice material for analyzing fingerprints:

This content is meant for Div C Forensics, but if you’re interested in learning the different methods to detect fingerprints, take a look at this document:

This activity is meant for Div C Forensics, but feel free to take a look for a complete analysis of blood splatters:

Review and Practice

The review problems at the top will help you ensure you’ve retained the content from the above resources, while the two tests at the bottom will help show you what to expect on a real Crime Busters test. For more practice tests, check out MIT Invitational, National Invitational, etc.

Some Other Tips

If the test writer list is released ahead of time, try to look for previous tests that they have written. If not, look at a test from the same invitational from the year before. This’ll give you a good idea of what the test might contain, whether it’ll just be repeated info from old tests, or be styled like an Among Us game where there’s a chat log instead of a suspect description. For example, I remember there was one specific test writer that always wrote scenarios where there were two perpetrators that worked together.

Color code your cheat sheet. If you’ve read ScioVirtual’s Create your cheatsheet with tips from pros article, you’ll already be aware of the benefits. For CB especially → since it’s split into different sections with plastics, fibers, and powders, color coding will make it much easier to find information.

Continuously add to your cheat sheet. There will always be random trivia that you don’t know for forensics, and sometimes they’ll constitute a pretty decent chunk of the test. After all, there’s only so much information you can add through Google.  Go back through after a competition and note down the problems that were marked incorrect to update the cheat sheet.

Some Examples