Crime Scene Investigation
The JCCL Crime Scene Investigation section responds to and processes a vast spectrum of crime scenes including homicides and other death investigations, sexual assaults, battery cases, robberies, burglaries, etc. Crime scene processing can take place at a business or residence or in a vehicle, in which case it may be processed on site or at the JCCL. Even people may be processed as a crime scene when their body or clothing is housing evidence of a crime. The section is well trained and capable of investigating any crime scene discovered in the cities or rural areas of Johnson County.
Documentation of a crime scene utilizes photography, diagrams, and written reports. The section also utilizes a 3-D laser scanner to quickly capture millions of data points at a scene. This allows investigators to virtually walk through a scene without the potential of cross-contamination, and preserves the scene forever for future examinations or trials. Evidence collection includes all forms of biological specimens, trace evidence, firearms related evidence and trajectory information, footwear, tire tracks, bloodstains, fingerprints, and any and all materials of evidentiary value found at a crime scene. Advanced techniques such as chemical enhancement and detection of blood and alternate light source use for detection of biological fluids or other trace evidence may also be utilized. The evidence, once collected, is submitted to the various sections of the laboratory for analysis.
Utilizing their photographs, diagrams, written reports, and the results of the evidence analysis, the members of CSI work with the various sections of the laboratory to reconstruct the events that transpired at the crime scene. They seek to answer the who, what, where, when, and how. Unlike on TV, typically the “why” is left to the investigating agency’s detectives.
One of the primary responsibilities of CSI is scene photography and other specialized types of evidentiary photography, and the section utilizes high-end DSLR and other specialized cameras for this task. But CSI also processes digital image cards or CDs received from law enforcement agencies and fire departments in Johnson County. While film is certainly being encountered less frequently, the laboratory will receive film photos or film found at a crime scene as evidence. The film may be color slide film, color negative film, or black and white film, and the sizes vary from 35mm up to 4” by 5” sheet film. Most agencies are now utilizing digital photography at this stage in the evolution of photo technology. Their evidence submission may be in the form of digital image cards or mini-CD’s. Whether film or digital, the evidence is processed and photo prints or a CD of the images is returned to the submitting agency. The section uses a hash-value program to verify all images at each stage of the process so that the value of the evidence is maintained.
Members of the section testify in court as requested and constantly strive to improve their end product. Training for section members is an on-going process to keep up with the most advanced investigative techniques.
In 2010, the JCCL Crime Scene Investigation became accredited for the first time at the JCCL under the ASCLD/LAB-International program. This makes the Johnson County Sheriff’s Office Criminalistics Laboratory among the first Sheriff’s Office organizations in the U.S. with an accredited Crime Scene Investigation section.