Wednesday, June 1

Family-Friendly Forensic Science Unit

Everybody loves a good mystery! Figuring out “who dun it” in the sixty or ninety minute time frame can be good family fun, but in reality it takes much longer to solve a crime. Have you ever wondered how forensic scientists use observation, evidence, and data to solve these crimes?

Forensics is the combination of different fields of science which work together to answer the questions a lawyer might ask in court. Usually these questions are about proving how a crime was committed and whether a suspect was present at the crime scene. Where serious crimes, like murder, are committed, the forensics of proving a suspect’s innocence can decide whether they go free. If a forensics team makes a mistake, the wrong person could be jailed, or worse. So you can see, science matters a lot in criminal investigations!

Diagnosing a Crime Scene

When a crime has been reported, detectives are sent to find evidence so they can begin solving it. The first thing they have to do is “seal the scene,” or preserve as much of the evidence as possible. When they get there, that have to figure out what happened, which isn’t always easy! Was it a robbery, a murder, or both? Witnesses are often scared and may not always know exactly what happened either. Detectives have to try and establish a sequence of events that happened before and after the crime was committed.

The next thing they do is begin to gather evidence. This isn’t easy either, and they need to get every single piece of evidence, no matter how small, and take samples away for further investigation. Items of evidence are stored in separate plastic bags and carefully labeled. Sometimes they have to take pictures, videos, and sketches, especially if it is in a public place that needs to be reopened. The really hard part here is knowing which evidence is important and which is just “other stuff.” They may find the robber’s fingerprints, but also the fingerprints of a hundred other people, and they have to decide who to follow up with and who is innocent.

If a death was involved, then the body may be sent to the medical examiner’s office for an autopsy. Our bodies are made of hard skeletons with soft tissues, which disintegrate quickly after death. If there is a question about the victim, the ME may use dental records or DNA to confirm who it is. If you are interested in pathology and autopsies, you can learn more about this at the links below.

Insert a link or something here to forensic pathology and autopsies in case don’t want to get gruesome


When detectives arrive at a crime scene, they spend a long time searching for as many clues as possible. Evidence can be anything that suggests someone was at the crime scene, and may include:
  • Footprints
  • Hair
  • Handwriting
  • Fingerprints
  • Blood
  • Tire tracks
  • Bullets / Weapons
  • Gun residue
  • Glass shards
  • Material / fibers
  • Liquids
  • Chemicals
  • DNA
  • Soil

Interviewing a Witness

Have you ever seen a news story about a crime, and the anchor follows up asking folks to call in if they have any information about what happened? This is an appeal for witnesses. Witnesses can be a very important part of a criminal investigation because they report what they saw and heard just before, during, or after a crime occurred.

Witnesses are interviewed both at the crime scene and after the fact. Statements are collected, written down, and signed by the witness to confirm they are true. Sometimes, though, a witness may THINK the statement is true, when it is actually not. People don’t always remember events accurately, especially when they are shaken, scared, or confused by what is happening. Generally, the longer it has been between the crime and the questioning, the more likely for the memories to have been altered.

Additionally, sometimes when suspects (people the police think were actually involved with the crime…not just a witness) are interviewed, they don’t tell the truth. Suspects may be interviewed repeatedly over a period of weeks or months to see if their stories remain consistent. If there is more than one suspect, they may be separated and interviewed to see if their stories match. Maybe on a TV show or movies, you’ve seen detectives use the "good-cop, bad-cop" routine. This is one example of a psychological technique used to get answers.

Different Types of Forensics

We each have different talents and strengths, and forensic scientists are no different. There are several different departments, each which specializes in a specific piece of evidence, but each department has one thing in common – their desire to accurately complete the investigation.
  • Forensic accountants study and interpret of accounting (money) evidence
  • Computational forensics uses the development of algorithms and software to look for patterns and solve crimes
  • Criminalists answer questions related to biological evidence (such as DNA), fingerprints, footwear impressions, tire tracks, controlled substances, ballistics and firearms, and other evidence that is processed in a crime lab
  • Digital forensic specialists use scientific methods and techniques to recover data from electronic / digital media
  • Forensic document examiners look at a disputed document using a variety of scientific processes, including handwriting analysis, authorship, and a comparison of the questioned document, or components of the document, with a set of known standards
  • Forensic pathologists use medical methods, including autopsy, to determine a cause of death or injury
  • Forensic psychologists study the mind of an individual to determine the circumstances behind a criminal's behavior
  • Forensic toxicologists study the effect of drugs and poisons on/in the human body

Who Dun It?

If you are REALLY into forensics, check out 'Who Dun It?'  This year-long language arts program lets you match your wits against the detective and see if you can discover who did it.  Using stories, including Hercule Poirot, Miss Jane Marple, Sherlock Holmes, Father Brown, and Lord Peter Wimsey, you will create your own detective and write your own murder mystery!  The first half of the year, students create their detectives, assistants, suspects, plot, setting, theme, clues, red herrings, and murderer, as well as write a short story.

Our 9th grader completed the Who Dun It? course this past year and absolutely loved it!  As a parent, I was pleasantly surprised at the caliber of story he turned out by the end of the year, and he enjoyed reading literature and watching movies that interested him (more than the traditional classics presented in high school language arts).  If you have a student who is looking for something a bit more engaging, this might be the perfect answer for you!

Download the Forensic Science unit for FREE on our Subscriber Freebies page!  Not yet a subscriber?  Sign up here!

Younger Kids Books

Older Kids Books


Make / Do


  • expert witness
  • autopsy
  • physical evidence
  • rigor mortis
  • autopsy
  • forensic odontology
  • chromatography
  • infrared
  • spectrophotometry
  • ultraviolet
  • anticoagulant
  • toxicologist
  • chromosome
  • DNA
  • short tandem repeats (STR)
  • anthropometry
  • whorl


  • Choose a real-life criminal investigation.  What kinds of evidence did forensic scientists use in solving this crime?
  • What kind of information can a forensic scientist learn from a mummy today?  What would they have learned a century ago?

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