Crime Scene Investigation Webquest



A Guide for General Crime Scene Investigation: Arriving at the Crime SceneInitial responding officers?who arrive at a crime scene should:Respond with caution.?Officers who arrive at a crime scene must be cautious and methodical. They should strive to preserve the scene with minimal contamination and should not disturb physical evidence.The responding officer(s) should:Note or log dispatch information (e.g., address/location, time, date, type of call and parties involved).Be aware of any persons or vehicles in or leaving the crime scene.Approach the scene cautiously, scan the entire area, and note any possible secondary crime scenes.Make initial observations (look, listen, smell) to assess the scene and ensure officer safety before proceeding.Remain alert and attentive.Treat the location as a crime scene until it has been assessed and determined to be otherwise.Follow safety procedures.?Officers must identify any dangerous situations or people to keep themselves and other individuals safe.The responding officer(s) should:Ensure that there is no immediate threat to?other responders— scan the area for sights, sounds and smells that may present danger (e.g., hazardous materials such as gasoline). If the situation involves a clandestine drug laboratory,?biological weapons, or?radiological?or?chemical threats?the officer should contact appropriate personnel/agencies before entering the scene.Approach the scene in a manner that maximizes the safety of victims, witnesses, officers and others in the area.Survey the scene for dangerous persons and control the situation.Notify supervisory personnel and call for assistance/backup.Provide for emergency care.?Officers should ensure that medical attention is provided to injured people, and minimize contamination of the scene.The responding officer(s) should:Assess the victim(s) for signs of life and medical needs and provide immediate medical attention.Call for medical personnel.Guide medical personnel to the victim to minimize contamination or alteration of the crime scene.Point out potential physical evidence to medical personnel, and instruct them to minimize contact with such evidence (e.g., ensure that medical personnel preserve all clothing and personal effects without cutting through bullet holes, knife tears, etc.).Document movement of persons or items by medical personnel.Instruct medical personnel not to clean up the scene and to avoid moving or altering items originating from the scene.Obtain the name, unit and telephone number of attending medical personnel, and the name and location of the medical facility where the victim is to be taken.If there is a chance the victim may die, attempt to obtain a?dying declaration or a statement about the circumstances surrounding his or her impending death.Document any statements/comments made by victims, suspects or witnesses at the scene.If the victim or suspect is transported to a medical facility, send a law enforcement official with the victim or suspect to document any comments made and preserve evidence. (If no officers are available to accompany the victim/suspect, stay at the scene and ask medical personnel to perform this task.)Secure and control people at the crime scene.?Officers should control, identify and remove people from the crime scene.The responding officer(s) should:Control all individuals at the scene — prevent individuals from altering or destroying physical evidence by restricting movement, location, and activity while ensuring and maintaining safety at the scene.Identify all individuals at the scene, such as:Suspects. Secure and separate.Witnesses. Secure and separate.Bystanders. Determine whether they were witnesses, if so treat as above, if not, remove from the scene.Victims/family/friends. Control while showing compassion.Medical and other assisting personnel.Exclude unauthorized and nonessential personnel from the scene (e.g., law enforcement officials not working the case, politicians and media).Identify, establish, protect and secure boundaries.?Officers can protect and secure a crime scene by defining and controlling its boundaries. Boundaries should be expanded beyond the initial scope of the crime scene with the understanding that the boundaries can be reduced in size if necessary.The responding officer(s) should:Establish the scene(s) boundaries, starting at the focal point and extending outward to include:Where the crime occurred.Potential points and paths of exit and entry of suspects and witnesses.Places where the victim/evidence may have been moved. Be aware of trace and?impression while assessing the scene.Set up physical barriers (e.g., ropes, cones, crime scene barrier tape, available vehicles, personnel, other equipment) or use existing boundaries (e.g., doors, walls and gates).Document the entry/exit of all people entering and leaving the scene, once boundaries have been established.Control the flow of personnel and animals entering and leaving the scene.Work to preserve and protect evidence that may be lost or compromised (e.g., protect from the weather, footsteps, tire tracks and sprinklers).Document the original location of the victim or objects that you observe being moved.Consider search and seizure issues to determine the necessity of obtaining consent to search and/or obtaining a search warrant.Note:?Within the boundaries of the scene, people should not:Smoke.Chew tobacco.Use the telephone or bathroom.Eat or drink.Move any items, including weapons (unless necessary for the safety and well-being of persons at the scene).Adjust the thermostat or open windows or doors. Maintain scene as found.Touch anything. Note and document any items moved.Reposition moved items.Litter.Spit.Turn over control of the scene and brief the?investigator(s) in charge. Responding officers should brief the investigator(s) taking charge to help control the crime scene and establish further investigative responsibilities.The responding officer(s) should:Brief the investigator(s) taking charge.Assist in controlling the scene.Turn over responsibility for the documentation of entries and exits from the scene.Remain at the scene until he or she is relieved of duty.Document actions and observations.?Officers should create a permanent record of all activities conducted and observations made as soon as possible after the event.The responding officer(s) should document:Observations of the crime scene, including the location of persons and items within the crime scene and the appearance and condition of the scene upon arrival.Conditions on arrival (e.g., lights on/off; shades up/down, open/closed; doors and?windows, open/closed; smells; ice, liquids; movable furniture; weather; temperature; and personal items.)Personal information from witnesses, victims or suspects. Any comments they make.Actions by the officer and others present.A Guide for General Crime Scene Investigation:Documenting and Evaluating the SceneOnce the?investigator(s) in charge?of the crime scene arrive, they should:Conduct a scene assessment.?The investigator(s) in charge should identify responsibilities, share preliminary information, and develop investigative plans in accordance with departmental policy and local, state, and federal laws.The investigator(s) in charge should:Converse with the?first responders about observations and activities.Evaluate safety issues that may affect all personnel entering thescene(s) (e.g.,?blood borne pathogens and/or hazards).Evaluate search and seizure issues to determine the necessity of obtaining consent to search and/or obtaining a search warrant.Evaluate and establish a path of entry/exit to the scene that can be utilized by authorized personnel.Evaluate initial scene boundaries.Determine the number/size of scene(s) and prioritize which should be investigated first.Establish a secure area within close proximity to the scene(s) for the purpose of consultation and equipment staging.If?multiple scenes?exist, establish and maintain communication with personnel at those locations.Establish a secure area for temporary evidence storage in accordance with rules of evidence/chain of custody.Request additional investigative resources as required (e.g., personnel/specialized units, legal consultation/prosecutors and/or equipment).Ensure continued scene integrity (e.g., document entry/exit of authorized personnel and prevent unauthorized access to the scene).Ensure that witnesses to the incident are identified and separated. Obtain valid ID.Ensure the surrounding area is canvassed and the results of this canvassing are documented.Ensure that the scene, injured persons and vehicles are documented and photographed.Conduct a scene walkthrough and initial documentation.?The investigator(s) in charge should conduct a walkthrough to identify threats to scene integrity and protect physical evidence. They should provide careful written and photo documentation.During the scene walkthrough, the investigator(s) in charge should:Avoid contaminating the scene by using the established path of entry.Prepare preliminary documentation of the scene.Identify and protect fragile and/or perishable evidence (e.g., consider climate conditions, crowds and/or hostile environment).Ensure that all evidence that may be compromised is immediately documented, photographed and collected.A Guide for General Crime Scene Investigation: Processing the SceneFollowing the walkthrough, the?investigator(s) in charge?should create an investigation team and process the scene. They should work with the investigation team to follow these steps:Determine team composition.?The investigator(s) in charge should determine which personnel and resources are needed on the investigation team to perform scene processing.The investigator(s) in charge should:Assess the need for additional personnel. Be aware of the need for additional personnel in cases of?multiple scenes, multiple victims, numerous witnesses or other circumstances.Assess forensic needs. Call forensic specialists to the scene for their expertise and/or equipment.Maintain scene security.Continue documenting entries and exits from the scene.Select qualified people to perform specialized tasks such as photography, sketches,?latent prints?and evidence collection.Document?team members?and assignments.Control?contamination.?The investigator(s) in charge must control contamination and?cross-contamination at scenes to ensure scene safety and evidence integrity.Team members should:Limit scene access to people directly involved in scene processing.Follow established scene entry/exit routes.Identify?first responders?and consider collecting?elimination samples.Designate a secure area for trash and equipment.Use?personal protective equipment (PPE)?to keep officers from harm and minimize scene contamination.Clean/sanitize?or dispose of tools/equipment and PPE between evidence collections and scenes.Utilize?single-use equipment?when collecting biological samples.Document the scene.?The investigator(s) in charge must ensure that the scene is documented, and determine the kind of documentation required (e.g., photography, video, sketches, measurements and notes).Team members should:Review the assessment of the scene to determine the type of documentation needed.Coordinate photographs, video, sketches, measurements and notes.Photograph:The entire scene utilizing overall, medium and close-up coverage.Evidence that will be collected with and without a?measurement scale and/or?evidence identifiers. Victims, suspects, witnesses, crowd and vehicles.Additional perspectives (e.g., aerial photographs, witness' view of the scene and the area under the body once the body is removed).Use videotape to supplement photos.Prepare preliminary sketch(es) and measure:The immediate area of the scene noting?case identifiers?and indicating north on the sketch.The relative location of evidence (correlate evidence items with evidence records).The size of the evidence before collection.The rooms, furniture or other objects.The distance to adjacent buildings or other landmarks.Generate notes at the scene that:Document the location of the scene, time of arrival and time of departure.Describe the scene as it appears.Record?transient evidence?(e.g., smells, sounds and sights) and conditions (e.g., temperature and weather).Document circumstances that require departures from the usual procedures.Prioritize evidence collection.?The investigator(s) in charge and the investigation team should prioritize evidence collection to prevent loss, destruction or contamination.Team members should:Conduct a careful and methodical evaluation that considers all physical evidence possibilities (e.g.,?biological fulids, latent prints and?trace evidence).Focus first on the easily accessible areas in open view and then proceed to out-of-view locations.Select a systematic search pattern for evidence collection based on the size and location of the scene(s).Select a progression of processing and collection methods so that initial techniques do not compromise subsequent methods.Concentrate on the most transient evidence and work to the least transient forms of physical evidence.Move from least intrusive to most intrusive processing and collection methods.Regularly assess environmental and other factors that may affect the evidence.Remain aware of multiple scenes (e.g., victims, suspects, vehicles and locations).Recognize other methods that are available to locate, document, and collect evidence (e.g.,?alternate light sources and blood pattern documentation).Collect, preserve, inventory, package, transport and submit evidence.?Team members should carefully collect, preserve, package and transport evidence.Team members should:Maintain scene security throughout processing and until the scene is released.Document evidence collection by recording its location at the scene, the date of collection and who collected it.Collect each item identified as evidence.Establish a?chain of custody.Obtain?standard reference samples?from the scene.Obtain control samples.Consider obtaining elimination samples.Immediately secure electronically recorded evidence (e.g., answering machine tapes, surveillance camera videotapes and computers) from the vicinity.Identify and secure evidence in containers (e.g., label, date and initial container) at the crime scene. Different types of evidence require different containers (e.g.,?porous,?nonporous?and crushproof).Package items to avoid contamination and cross-contamination.Document the condition of firearms/weapons prior to rendering them safe for transportation and submission.Avoid excessively handling the evidence after it has been collected.Maintain the evidence at the scene in a manner designed to diminish degradation or loss.Transport and submit evidence items for secure storage. ................
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