Science of Crime Scenes Chapter 3.0 Science of Crime Scenes

Science of Crime Scenes Personnel CSI typically must have a minimum of a four-year degree in science Many have advanced degrees and even internships with forensic agencies A new employee will need time, experience, and training The training will be a mixture of in-house and external training The training has to be continuous, as the field of forensic science changes constantly Science of Crime Scenes

Post-Traumatic Stress Disorder (PTSD) for CSIs The physical and psychological problems that may be experienced by first-responders, such as police officers have also been well documented Police, firefighters, and medical personnel No specific research regarding CSIs' stress levels after processing traumatic death events exists Not considered in the first responder category May be overlooked because they respond from the laboratory Science of Crime Scenes

Physical responses to trauma Stomach upset and trouble eating Trouble sleeping and feeling very tired Pounding heart Rapid breathing Feeling edgy, sweating, severe headache if thinking of the event Failure to engage in exercise, diet, safe sex, regular health care Excess smoking, alcohol, drugs, and food Science of Crime Scenes

Emotional responses to trauma Feeling nervous, helpless, fearful, or sad, Feeling shocked, numb, and not able to feel love or joy Avoiding people, places, and things related to the event Being irritable or having outbursts of anger Becoming easily upset or agitated Blaming yourself or having negative views of oneself or the world Distrust of others Getting into conflicts, being over-controlling, being withdrawn Feeling rejected, or abandoned, loss of intimacy or feeling detached Science of Crime Scenes

Science of Crime Scenes What help is available An agency psychologist Critical incident stress debriefing (CISD) Employee assistance program (EAP) If after treatment the CSI decides to leave the team, this should not reflect on his reputation in a negative way Long-term crime scene investigation is not for everyone Science of Crime Scenes

Science of Crime Scenes Contamination Only a few cells are needed to detect a useful DNA profile Therefore, only a few cells are needed to contaminate a DNA sample The principal sources of DNA contamination are: from personnel to the exhibit/DNA sample from contaminated consumables (for example, swabs, tubes, personal protective equipment (PPE)/ barrier clothing) to the exhibit/DNA sample from exhibit to exhibit or DNA sample to DNA sample from contaminated equipment not properly cleaned from previous scenes (for example, cameras, tripods, step plates). Science of Crime Scenes

How contamination occurs Directly For example, saliva or dandruff from an examiner ending up on an exhibit Indirectly For example, biological material present on a drawer handle is transferred on to the gloves of an examiner who opens the drawer, fails to change their outer pair of gloves and then handles a significant item, resulting in the indirect transfer of biological material from the handle of the drawer to the item) Science of Crime Scenes

How to avoid contamination Limit attendance at crime scenes to absolutely only the essential responders Make sure everyone wears protective clothing that is also designed to limit transfer of evidence, such as booties, head covers, vinyl gloves Use disposable evidence collection tools such as plastic forceps Use disposable pens and writing materials Thoroughly clean cameras and other documentation equipment between crime scenes Science of Crime Scenes

Use off-site facilities No matter how urgent, do not satisfy your biological needs at the crime scene. Whenever you need to eat, drink, or go to the bathroom, and even if you must smoke use off-site facilities. Science of Crime Scenes

The Iron Triangle of Success Cost Time Quality CSIs have limited resources and must work optimally with what is available Science of Crime Scenes

Science of Crime Scenes Team vs. Ego Team: two or more people who are working together. Ego: your sense of your own value and importance; the part of the mind that is responsible for your sense of who you are. Individuals need to sufficiently suppress their egos to the team’s ultimate goal of a successful crime scene Each team member contributes to the success of investigation Each has a specific role and may not be employed by the investigating agency, but you must work with the other team members to accomplish the overall objectives Individuals must never lose sight of the bigger picture Science of Crime Scenes