crime scene investigation


Make Real-World Connections and Engage Students

When crime scene investigators collect and analyze evidence from the scene of a crime, they are applying forensic science. By using tools from physical science, biology, and math, investigators are able to recreate and analyze the elements of a crime scene. Forensic science allows law enforcement officials to determine the guilt or innocence of an accused person and courtrooms to uphold criminal laws.

If you’re looking to make a lasting mark on your students through an interdisciplinary science, look no further. Discover the many specializations within forensics that will captivate students as they learn techniques applied in the field.

Field Forensic Analysis

In field forensic analysis, crime scene investigators meticulously document and analyze the evidence they find at the scene of a crime. This procedure can vary depending on the type of crime; however, certain elements apply to all protocols. During a crime scene walkthrough, investigators photograph, sketch, film, and record detailed notes that can be used for evidence. They then search for trace evidence: fingerprints, shoe impressions, bloodstain patterns, bullet holes, hair, and fibers. Once the evidence has been documented, technicians use forensic tools to analyze it.

Additional Reading: Give Your Students Real-World Experiences with Authentic CSI Tools


Evidence Collection

Crime Scene Photographers

Crime scene investigation begins with the primary step: evidence collection. In order to effectively document the scene, investigators use photography, video, and sketches. With photography, investigators use different types of techniques to produce high-quality images that document both the evidence and scene. Our partner Sirchie® can help you understand camera settings and lighting techniques professionals use in the field. Use our activity to put those techniques into action!

Activity: Five Photography Terms Every Arson and Crime Scene Photographer Should Know

Carolina Crime Scene Bundle

Chain of Custody Evidence Envelopes

Photo Evidence Scales

Yellow Evidence Marking Flags, Pack of 100

Photo Evidence Numbers, Set of 15

Latent Fingerprinting

A crime scene brush dusting black talcum powder revealing a fingerprint mark on isolated white background.

Latent fingerprints are prints caused by natural secretions of the skin, which are not visible to the naked eye. Although invisible, the prints can be developed through a physical or chemical process. Several factors must be taken into consideration when choosing the correct process by which to make these prints appear. We can help you gain an understanding of latent fingerprinting and show you a few tips and tricks to help bring out the best in your prints.

Arriving on the Scene: Forensic Science from the Pros

Activity: Development of Latent Fingerprints with Silver Nitrate

Leave Your Print: Basic Fingerprinting

Latent Print Development with Powders Kit

Forensic Chemistry of Fuming for Fingerprints Kit

Crime Scene Investigation Lab Kit

Standard Magnetic Fingerprint Powder Applicator

Black Magnetic Fingerprint Powder, 1 oz

Megawand Magnetic Fingerprint Powder Applicator

Fiberglass Fingerprint Brush

Fluorescent Orange Powder, 2 oz

Footwear Impression

Crime scene investigation – a footprint of criminal.

Impressions left by footwear at a crime scene can be used as evidence in an investigation. In some cases, footwear impressions can reveal substantial information. The type of shoe, the pattern of footprints left behind, and types of surfaces (mud, sand, a biological fluid) can all be important clues. Let the pros show you how to perform impression casting—just one of the techniques found in our kits.

Footwear Identification and Casting Kit

Footwear Impression Analysis Kit

Bio-Foam® Impression Foam, Single

Shake-N-Cast™ Kit

EZID™ Footwear Impression System

Bio-Foam® Impression Foam, Double

Bloodstain Analysis

A forensic scientist examines bloodstain evidence.

By researching and cataloging bloodstain patterns, scientists are better able to understand the actions involved in violent crimes. Scientists also use physics and math to analyze patterns so they can determine at what angle the blood hit a surface and from where it originated. Knowing this allows scientists to restage the actions of a crime. Learn more about bloodstain pattern analysis with our activity.

Activity: Bloodstain Analysis: Student Investigation Sheet

Bloodstain Pattern Analysis Kit

Where’s the Victim? Blood Spatter Analysis Kit

Carolina Beyond the Tape™: Crash in the Night Biology Kit

The Mystery of Lyle and Louise: Blood Spatter Analysis Kit

The Case of the Murdered Mayor Kit

Presumptive Blood Test Kit

Blood Detection BioKit®

Bullet Trajectory Investigation

Bullet penetrating a wooden surface

When a firearm is used in a crime, bullet trajectory and shooting reconstruction allow investigators to use trigonometry to calculate the angle of trajectory. Learn about projectile motion, bullet entry/exit patterns, and angle of incidence with mock bullet perforations in our ballistics activity.

Activity: Ballistics: Student Investigation Sheet

Bullet Trajectory Investigation Kit

Where’s the Shooter? Bullet Trajectory Kit

Carolina Beyond the Tape™: Golden River Heist Physics Kit

Basic Firearm Identification Kit

Bullet Display Set

Inert Display Cartridges

Laboratory Forensic Analysis

After being properly documented by crime scene investigators, evidence is transported to a forensic laboratory for testing and analysis. Scientists with a broad range of specializations—in pathology, toxicology, firearms, forensic biology, latent evidence, and trace evidence, to name a few—make up the staff in a typical forensic lab.

These staff members analyze evidence from the crime scene with sophisticated equipment, including mass spectrophotometers, DNA sequencers, scanning electron microscopes, and modern photography equipment. Next, the staff interprets evidence from chemical and physical tests to reconstruct a crime scene. The laboratory analysts prepare in-depth written reports of their findings and may also be called upon to testify in court.

Chain of Custody: From the Field to the Lab

Young scientist works in modern biological lab


DNA Fingerprinting

Female researcher examining DNA autoradiogram gel in laboratory

To distinguish a source of DNA from another, you can create a DNA Fingerprint profile. Small regions of repetitive DNA vary from person to person. This principle can be extended to the entire genome—no 2 profiles are alike with the exception of identical twins.

A sample of DNA can be isolated from blood, semen, saliva, or hair. The sample is then subjected to several different processes until the DNA sequence is visualized on an x-ray film by autoradiography. The banding pattern between samples can be compared for similarities to implicate or exonerate certain suspects.

Take a look at our activities and videos that discuss some of the techniques used in a DNA fingerprint profile.

Activity: Genetic Witness

Exploring Electrophoresis and Forensics Classroom Kit

DNALC Forensic DNA Fingerprinting Kit with GelGreen™ (with prepaid coupon)

PCR Forensics Simulation 8-Station Kit

DNALC Forensic DNA Fingerprinting Kit with CarolinaBLU™ (with prepaid coupon)

Using Highly Variable Polymorphisms in Forensic Biology and Population Genetics DNA Extraction and Amplification Kit with 0.5-mL Tubes (with prepaid coupon)not available for purchase

Forensic PCR Investigation Amplification and Electrophoresis Kit with CarolinaBLU™ (with prepaid coupon)

Outbreak! Fingerprinting Virus DNA 8-Station Kit


Screening for controlled substances in the bodily fluids of a suspect can provide additional evidence to piece together a crime scene. One of the most common types of screens for controlled substances is a urine dipstick, which typically screens for cocaine, marijuana, opiates, amphetamines, and phencyclidine. This test is based on an immunoassay that uses antibodies to detect specific chemicals.

For instance, in the case of marijuana, the active component is tetrahydrocannabinol (THC). When an antibody binds to a specific chemical, in this case THC, it causes a color change. These tests are usually confirmed with quantitative methods such as gas chromatography/mass spectrometry (GC/MS).

Read more about toxicology.

Article: Forensic Toxicology: The Dose Makes the Poison

Blood Alcohol Determination Kit

Drug Analysis Kit

Drugs and Poisons Analysis Kit

Introduction to Toxicology Kit

Carolina™ Forensic Dissection Kit for a Class of 32

Forensic Chemistry of Drug Detection Kit

Gunshot Residue: Scanning Electron Microscopy (SEM)

GSR (gun shot residue) test being conducted on a murder suspects left hand.

Gunshot residue (GSR) tests for trace chemical components found in gunpowder. When a firearm is discharged, it ejects dust containing these components that can remain on the hands and clothing of a person(s) within the vicinity. Nitrates, a type of trace chemical found in GSR, are commonly screened. During screening, gunshot residue pouches are used, and a chemical reaction using the organic compound diphenylamine produces a blue color in the presence of nitrates.

Further testing can be done on GSR particles collected from hands or clothing using a method called scanning electron microscopy (SEM). Through this method, trained technicians can identify particles by size, shape, and chemical make-up.

For more information on GSR, GSR forensics, and analytical techniques, view a presentation by our partner Sirchie®.

PDF: Understanding Gun Shot Residue

Gunshot and Explosive Residue Testing Kit

Gunshot Residue Presumptive Test Kit

Trace Powder Evidence Inquiry Kit

Basic Firearm Identification Kit

Bullet Comparison Poster

Cartridge Case Comparison Poster

Microscopy: Hair Evidence Analysis

Scientists proving the DNA from the hair in the lab.

Hair evidence can provide valuable information for recreating a crime scene because hairs can be transferred from person to person. Samples can then be analyzed to determine if the they belong to the victim, suspect, or another person. Using light microscopy, a trained technician examines features of the hair sample to determine if it is human or animal, from what part of the body it originated, its growth phase, and if human, the race, gender, and age of the person it came from.

Check out our hair analysis activity for a great introduction to forensics using microscopy.

Activity: Under the Microscope: Get Forensic with Hair Analysis

Hair Analysis Kit

Fiber Identification Kit

Microscopic Forensics Kit

His Hair, Her Hair, Whose Hair? Kit

Color Atlas and Manual of Microscopy for Criminalists, Chemists, and Conservators Book

Blood-Typing/Presumptive Blood

Drop of blood, close-up

Crime scene technicians may encounter blood when documenting a crime scene or recording items as evidence. It is often necessary to distinguish whether a sample is human blood. In order to accomplish this, technicians use a chemical screen like the Kastle-Meyer test, which uses the chemical indicator phenolphthalein to produce a purple color in the presence of hemoglobin. This is called a presumptive test.

Once a technician confirms that a sample is blood, another test such as blood-typing can be performed. Blood-typing works on the principle that red blood cells have surface molecules that allow the body’s immune system to recognize foreign cells from native cells. Foreign cells have molecules known as antigens on their cell surface, to which the immune system responds by producing antibodies. The antibodies attack and destroy the antigens, which results in a “clumping” of the blood, or agglutination.

Infographic: What’s Your Blood Type?

PDF: Carolina LabSheets™: Introduction to Blood Types

Carolina Synthetic Blood: Paternity Test Kit

Carolina Beyond the Tape™: Crash in the Night Biology Kit

Carolina™ ABO-Rh Typing with Synthetic Blood Kit

Blood Detection BioKit®

Presumptive Blood Test Kit

Carolina™ Forensics Mystery with Synthetic Blood Kit

Chemical Development of Prints

Depending on the type of secretions left behind on a print, a technician may use one or more chemical development techniques. Chemical developers such as iodine, 1,8-Diazafluoren-9-one (DFO), ninhydrin, and silver nitrate can be used to bring out the print. However, the chemical properties of these developers may alter the fingerprint—it is important to use them in a specific sequence.

Engage your students with an activity that allows them to develop their own fingerprints.

Activity: Development of Latent Fingerprints with Silver Nitrate

Chemical Development of Latent Prints Kit

Forensic Chemistry of Fuming for Fingerprints Kit

Latent Print Development with Powders Kit

Crime Scene Investigation Lab Kit

Standard Magnetic Fingerprint Powder Applicator

Related Links:

Leave a Reply