Detectives use a variety of means to collect crime scene evidence. When attempting to locate evidence, investigators must be methodical. One way to be certain they’ve combed every inch of a crime scene is to conduct structured, patterned searches, such as spiral or grid searches.
Spiral search patterns are an effective means of locating evidence.
Grid search patterns are especially effective when searching large areas, such as a field or other open land areas. Each grid block is assigned a number or letter. Detectives use those identifiers as reference points when testifying in court. Example: “I located the murder weapon in block number 4. I also discovered spent bullet casings in block number 3.”
Alternate light sources (ALS) are useful when attempting to locate hard-to-see evidence, such as fingerprints and body fluids. Devices such as Sirchie Fingerprint Laboratory’s Krime Site Imager are invaluable for detecting and capturing fingerprint images. The KS Imager is battery operated and is capable of recording images in bright light or in total darkness.
All too often, fingerprints are destroyed during crime-scene processing (dusting and lifting prints) Using a device such as the KS Imager allows investigators the opportunity to photograph a perfect image of a fingerprint before attempting dust and lift it. Therefore, even if the print is marred, detectives will still have perfect image of the print, an image that’s permissible as evidence.
A detective uses a Krime Site Imager to locate and photograph fingerprint evidence.
Some crime scenes, such as labs used for manufacturing methamphetamine, contain hazardous materials, such as flammable and toxic chemicals and fumes. When searching those dangerous crime scenes, investigators must wear protective gear and clothing.
A detective wearing a hazmat suit gathers evidence from a meth lab.