Crime scene investigation is one of law enforcement’s most prominent responsibilities. And while many of the skills required for successful investigations are taught in basic training, it’s wise to consider an occasional refresher course given today’s constantly evolving technology and investigation procedures.
The Attorney General’s Ohio Peace Officer Training Academy (OPOTA) offers a Basic Crime Scene Investigation course that covers this topic in depth. In addition, agencies that don’t have the resources to collect and process crime scene evidence can seek assistance from the Attorney General’s Bureau of Criminal Investigation (BCI), which is available at no cost.
It’s crucial for investigators to remember that, once responding officers have secured a crime scene, law enforcement
must get a warrant before entering and searching the area.
There is no “crime scene exception” to the Fourth Amendment’s warrant requirement. To ensure your search is constitutional and evidence won’t be suppressed, get a warrant.
Once a warrant has been secured, here are your next steps:
-
Take a preliminary survey of the crime scene to evaluate the possibilities for potential evidence. Create a narrative of the scene, being as detailed as possible. Write down the exact times you learned of the crime, arrived at the scene, and cleared the scene. Keep a record of the personnel who are present during the investigation.
-
Note all of your observations. Document (1) the presence or absence of any expected or unexpected items; (2) the lighting and weather conditions; (3) whether doors and windows are open or shut, locked or unlocked; and (4) any odors you may notice. Also note any victim, witness, or suspect who was interviewed or arrested.
-
Begin searching for and collecting physical evidence, including photographs of the scene; fingerprints; footwear impressions; tire impressions; firearms; DNA; trace evidence such as hair, fibers, and paint chips; and any other evidence. Investigators should practice the latest procedures in collecting and preserving these various pieces of evidence.
-
For example, when taking photographs, use a digital camera for crime scene and evidence photos; it doesn’t require a photo log. The camera records the date and time of the photo and embeds that information in the digital file.
-
If photographing a crime scene, begin by taking wider shots of the overall scene and then proceed with close-up shots of specific areas. Photograph the room or scene from eye level. When photographing evidence, take a close-up picture from above — at 90 degrees to the evidence. Include a photo evidence scale if one is available. If not, use a tape measure, ruler, or even a quarter to illustrate the size of the item being photographed.
-
When collecting fingerprints, take pictures of them before trying to lift them, and include both a scale and a placard in some of the photos. There are three types of fingerprints to search for: (1) patent prints, which are visible without enhancement; (2) latent prints, which are visible only with enhancement; and (3) plastic prints, which are visible only in a pliable material, such as window putty, a bar of soap, or tape.
-
For prints that require enhancement, investigators have a number of tools at their disposal to enhance and lift the best possible prints. The most common tool is conventional fingerprint powder. Also available are magnetic powder, fluorescent powder, cyanoacrylate (super glue), and iodine fuming. Once you’ve enhanced the prints, the most standard ways to lift them are with tape, casting putty, casting silicone, and school glue. Place the lifted prints on a transparency sheet while noting their exact original location and orientation.
-
It’s also crucial to package evidence properly for trial. Use breathable packaging materials and seal the packages with tape to prevent evidence contamination. Label the package with your name, the address where it was collected, the date of collection, the contents of the package, and your initials across the taped seal to verify you collected and packaged the evidence.
-
Finally, write a report of your work and take a final survey of the area before releasing the scene.
For more information about OPOTA’s Basic Crime Scene Investigation and other courses, visit
www.OhioAttorneyGeneral.gov/OPOTA or
www.OHLEG.com or e-mail
askOPOTA@OhioAttorneyGeneral.gov. For assistance with crime scene investigations, contact BCI at 855-BCI-OHIO (224-6446).
Morgan A. Linn
Assistant Attorney General and Legal Analyst