Crime Scene Investigation - Central Bucks School District

1 Crime SceneInvestigationMarilyn T. MillerIntroductionFrom nanogram quantities of DNA to artificial intelligence data-bases capable of identifying latent fingerprints, forensic scienceand the analysis of very minute quantities of physical evidencehave advanced and improved. Yet, these applications of the scienceare remote from the Crime Scene and its Investigation . Crime sceneinvestigation is the beginning point for the successful use of physicalevidence by the forensic laboratory and the criminal more than ever, the Scene of a Crime must always be properlymanaged and investigated in the best possible , high quality Crime Scene Investigation is a simple,methodical process.

2 It is not rigid; it follows a set of principles andprocedures that are reasonable and ensure that all physical evidenceis discovered and investigated with the result that justice is basic Crime Scene procedures are physical evidencerecognition, documentation, proper collection, packaging, preser-vation, and, finally, Scene reconstruction. Every Crime Scene isunique and, with experience, a Crime Scene investigator will be ableto use this logical and systematic approach to investigate even themost challenging Crime scenes to a successful a Crime SceneThe only thing consistent about Crime scenes is their of their diversity, Crime scenes can be classified in manyways.

3 First, Crime scenes can be classified according to the location ofthe original criminal activity. This classification of the Crime scenelabels the site of the original or first criminal activity as the pri-mary Crime Scene and any subsequent Crime scenes as classification does not infer any priority or importance to thescene, but is simply a designation of sequence of *t93-1246-9AB/$ +$ by CRC Press LLC115 forensic Science: An Introduction to Scientific and Investigative Techniquesi ^s_ ___ _____ jp, OUOf.

4 ,x ^kPhysical Evidence> Ob/\ \rpSr116gunshot residue, etc.) are especially well suitedfor determination of The identification of unknown substancesis a common use of physical of drugs, poisons, and evenbacteria such as anthrax are good step in the forensic examination Crime Scene investigator is frequentlymore interested in how a Crime occurred thanidentifying or individualizing the evidence atthe Scene . The "how" of the Crime Scene ismore important than the "who.

5 "Science and Crime SceneInvestigationsComparison TestingEvaluationInterpretationReporting and PresentationFigure Steps to the scientific examination of acrime Crime SceneProceduresScene ManagementCrimes today are solved by the teamwork ofinvestigators and Crime Scene personnel andby the combined use of techniques and proce-dures recognizing the power of Crime scenes,physical evidence, records, and , numerous cases, routine andcomplex, have shown that despite availablecrime Scene technologies and specially trainedpersonnel, the productiveness of a Crime sceneinvestigation is only as good as the supportivemanagement team.

6 The four distinctive butinterrelated components of 1. Information management2. Manpower management3. Technology management4. Logistics managementDeficiencies, negligence, and overemphasisof any one of these components will imperil theoverall Crime Scene Investigation . Thesecomponents are all based on the fundamentalneed for good and ongoing communicationFirst Responding OfficersThe first responders at a Crime Scene are usually police officers, fire department personneor emergency medical personnel.

7 They are thonly people who view the Crime Scene in itoriginal condition. Their actions at the crimscene provide the basis for the successful cunsuccessful resolution of the investigatioiThey must perform their duties and remenber that they begin the process that links vi<tims to suspects to Crime scenes and musnever destroy the first responders must always mailtain an open and objective mind when a]preaching a Crime Scene . Upon arrival, safelis a primary concern.

8 When the Scene and tlvictim are safe, the first responders mu: Patrol officers and detec- Useful if resources and tivesserve as Crime Scene demand are relatively lowtechnicians118 DescriptionModel TypeDisadvantagesAdvantagesSpecially trained full-time civilian personnelFull-time, sworn officerssiDie, they should initiate Crime scenesecurity measures. The duties of a first re-sponder are to:1. Assist the Search for and arrest the suspect ifstill on the Detain all witnesses because theypossess valuable information aboutthe Crime Scene .

9 Keep witnesses sep-arated to preserve their Protect the Crime Scene . Begin byusing barrier tape, official vehicles, orother means to secure the a Crime Scene security logto record the names of all personswho enter or exit the Crime Scene . Donot smoke, drink, or eat within thesecured Crime Scene and do not allowunnecessary persons or officials toenter or contaminate the Note and communicate to Crime sceneinvestigators all movements andalterations made to the Crime the Crime SceneThe Locard Exchange Principle is the basisfor linking physical evidence from or to thevictim, suspect, and Crime Scene .

10 Anyone en-tering a Crime Scene can alter or change thescene and its evidence, so access to the crimescene must be restricted and, if possible, pre-vented except for essentiial Crime Scene per-sonnel. Any physical barriers like vehicles ortapes that help protect the Crime Scene mustbe established as soon as possible by the Scene barriers have been established,one officer shall be designated as the scenesecurity officer. He or she will be responsiblefor preventing entrance into the Crime Scene bycurious onlookers.