DGO6.02 "Physical Evidence and Scene Preservation"

6.02.01 PURPOSE

The purpose of this order is to describe the policies and procedures for determining what constitutes a crime scene or major incident scene and recognizing, preserving, and booking physical evidence

6.02.02 DEFINITIONS

A. Crime Scene or Major Incident Scene – A crime scene or major incident scene is a location at which there has been an event involving potential or actual injury, death, or property damage requiring an exceptional emergency response. This includes noncriminal natural disasters (floods, earthquakes, major fires, etc.) and human-caused emergencies (major traffic collisions, industrial accidents, plane crash, riot, terrorist acts, hostage situations, high profile events which may cause public unrest etc.), which require extensive response and commitment of resources to control or resolve. An incident scene where a Critical Incident has been declared is a Major Incident crime scene (See DGO 8.01, Major and Critical Incident Evaluation and Notification) and includes not only the area where the criminal or non-criminal act occurred, but also approaches and exits that the suspect(s) may have used, i.e., point of entry and exit. Not all evidence is visible.

B. Physical Evidence – Physical evidence is anything that has been used, left, removed, altered, or contaminated during the commission of a crime or incident by the victim(s) or suspect(s) or involved parties. 

C. Buccal swabs – swabs taken from the inside of a person’s mouth for use as a DNA reference sample. 

D. Contact swabs – swabs taken from an individual (hands/fingers/fingernails or other body parts) for potential evidence. 

E. Chain of Custody – Chain of Custody refers to the documentation of who had possession of the evidence, from the time of collection to the time of analysis and beyond. 

F. Critical Evidence – Evidence that merits careful consideration and protection due to its potential relevance, or fragility or sensitivity to contamination. These items may include deceased bodies, biological material, footprints, fingerprints, tire tracks, fibers, and other trace evidence.

G. Digital Evidence – Digital evidence includes all media capable of storing data including mobile devices, computers, game consoles, hard/solid state drives, drones, optical media, and flash media. 

H. Questioned Documents – Questioned documents are checks, credit card receipts, threat and extortion letters, robbery notes, business records, etc.

6.02.03 POLICY

A. Preventing Contamination of the Crime Scene and Major Incident Scene – It is the policy of the San Francisco Police Department (SFPD) to ensure that crime scenes are preserved for investigation and for the collection of uncontaminated and undisturbed evidence. Physical evidence shall be collected using methods that maintain, to the furthest extent possible, the integrity of the piece of evidence for further analysis. SFPD policy follows the guidance of national accrediting agencies and organizations, as well as that of experts in the field. The careful and proper preservation, collection and booking, and the documentation of chain of custody for all evidence collected, is critical to investigative efforts and to later court cases. (See DGO 8.11, Investigation of Officer Involved Shootings and Discharges)

B. Chain of Custody – The legal requirements for evidence that will be introduced into court may be more stringent than the requirements for evidence that is used solely to justify an arrest. Officers shall, at all times, maintain and document the chain of custody.

6.02.04 PROCEDURES

PRESERVING, COLLECTING, AND TRANSPORTING PHYSICAL EVIDENCE AT CRIME SCENES / MAJOR INCIDENT SCENES

A. Recognizing a Crime Scene or Major Incident Scene– Members shall contact the Crime Scene Investigations (CSI) or specialized investigative unit if any questions arise as to the scope of an incident scene and/or physical evidence. It is the responsibility of first responding officers at the scene to notify the Department Operations Center (DOC), when applicable, or CSI, if there is potential for recovering physical evidence or a need for specialized documentation, handling, and processing. If CSI is responding, members shall take steps to ensure that the potential evidence is protected.

B. Roles and Responsibilities of Investigative Units

1. Specialized Investigative Units – When required, specialized investigative units shall respond to conduct investigations into criminal and some non-criminal incidents as outlined by current policy. If an Investigator is responding to a scene, members shall make every effort to preserve the scene and evidence within.
2. Crime Scene Investigations Unit – CSI is a specialized unit composed of Crime Scene Investigators who have extensive forensic training. CSI personnel are on-duty seven days a week from 0600-2400. After hours, for scenes that meet CSI call out criteria, on-call CSI personnel will be notified through DOC and will respond to crime scenes and major incident scenes which require immediate, specialized documentation or processing.

C. Identifying and Preserving Crime Scenes and Major Incident Scenes – It is the responsibility of responding officers to isolate and protect crime scenes and major incident scenes from contamination until relieved by a superior officer or designated investigating officer. 

Members must use their experience and judgment to determine when a major incident scene must be preserved and documented. Members may contact specialized units who may have an interest in the scene (such as S.I.D., Homicide or TCIU) for guidance as necessary.

D. Establishing Route into Crime Scenes – The officers assigned to protect the crime scene or major incident scene shall determine route(s) into the scene which ensure the safety of personnel on scene and minimizes disruption to the physical evidence within the scene. This route shall be relayed to dispatch as soon as possible to prevent officers and emergency personnel from disturbing the crime scene. All personnel shall enter and exit the crime scene using the established route(s), if possible. 

E. Initiating the Incident Log – Once it has been determined that a crime or major incident scene must be protected, first responding officers shall initiate an Incident Log (SFPD 28A). This log shall be maintained until all personnel have left and containment ends. The officer initiating the log should, as soon as is reasonably possible, record the incident number, type of incident and location of the incident on the incident log. The officer maintaining the log is responsible for recording the name and position of each person who enters the crime scene, their reason for entry, and the time they entered and exited the incident scene. 

F. Preserving the Scene

1. At all crime scenes and major incident scenes, the outer perimeter of the scene shall be marked using yellow crime scene tape. First responding officers on scene shall determine the outer perimeter of the scene based on the nature of the incident, possible movements at the scene by involved parties, and the possible location of physical evidence.
2. At all crime/major incident scenes, officers shall canvas for areas which may require special processing, such as the presence of critical evidence. These areas with critical evidence may be cordoned off with red crime scene tape. Areas within the red crime scene tape shall remain undisturbed if possible. Entry into these critical evidence zones must be restricted to necessary personnel only.

G. Moving Evidence – Officers shall not move evidence at a crime scene or major incident scene unless the evidence is in danger of being lost, contaminated, or destroyed, or when a weapon must be secured to ensure the officer's safety or the safety of others. The mere fact that a weapon is loaded and/or cocked does not in itself justify moving the weapon. 

If it is necessary to move evidence, ensure fresh latex or nitrile gloves are worn and carefully document its original position and condition. When possible, photograph evidence in place prior to moving it. Notify the Investigators upon their arrival and record the details in your incident report.

H. Collecting Evidence – At non-major crime scenes, when specialized units are not required, the responsibility for proper collection of physical evidence rests with the responding officers present. An example of this is officers collecting fired cartridge casings from shot spotter activation calls.

Many items of physical evidence can be processed for latent fingerprints and/or examined for other trace evidence or DNA. Use caution when collecting and handling evidence to ensure that such items are disturbed as little as possible, and the evidence is preserved. Members shall wear fresh latex or nitrile gloves when handling any physical evidence; both to protect the evidence from potential contamination and to protect themselves. CSI members shall ultimately determine if a response to collect evidence is warranted. CSI will only collect items of evidence if further forensic examination is to be conducted, or there is a specific need for CSI to collect and book the item.

If private or public property must be damaged or destroyed to recover evidence, it is the responsibility of the investigator assigned to the case to authorize the destruction and document the investigative reason the damage or destruction was required in a memorandum. The memorandum is to be forwarded to the Risk Management Office.

1. Underwater Recovery of Physical Evidence – Whenever possible, firearms, knives, tools, digital evidence, and other metal objects recovered from underwater should be kept in the water in which they were submerged and not exposed to the air. For example, a pistol recovered from the Bay should be kept in a bucket of Bay water when brought to the surface. Members shall contact CSI for instructions for transporting and booking metal objects found underwater prior to leaving the incident scene. (See DGO 6.03, Underwater Diving Operations) 

2. Ballistic Evidence at Incident Scenes – Members shall not touch or remove fired bullets, fragments, cartridges, or cartridge casings, if feasible, unless directed to do so by a member of the CSI unit or by the Investigator assigned to the case. 

   When directed to recover ballistic evidence from a scene where no specialized unit or CSI is responding, evidence shall be collected as follows:

   Prior to moving any ballistic evidence, the officer shall photograph the evidence in place, document the location and include that information in the incident report. Members shall always wear fresh latex or nitrile gloves prior to handling ballistic evidence. The officer shall then transport the evidence in a suitable container (preferably paper). When booking ballistic evidence, members shall mark the container and not the evidence to eliminate the possibility of destruction of minute evidence, such as DNA, stria, ejector, extractor, or magazine marks.

3. Gunshot Residue (GSR) – Where there has been a crime involving the use of a firearm, GSR samples may be taken to determine the presence of gunshot residue on the suspect's hands. GSR is fleeting evidence; ideally GSR should be collected as soon as possible. GSR can be collected without the need for a warrant as a search incident to arrest, or pursuant to a warrantless search condition, or with lawful consent, or if there is an exigency based on the totality of the circumstances. If the subject being tested must be transported prior to collection of GSR, members shall place hand bags over their hands and secure with zip ties. Members shall not allow the subject to use the washroom or go to the bathroom unescorted until the administration of the test. Long sleeve clothing may also be booked for later analysis of gunshot residue. (See Department Notice procedures on Gunshot Residue Collection).
4. Reference Buccal Swabs – Members shall read the consent statement provided as part of the DNA collection kit before collecting reference buccal swabs. It is the responsibility of officers collecting buccal swabs to book the swabs. Reference buccal swabs collected from victims, witnesses or elimination samples shall only be used for comparison to forensic evidence in the case they are collected for and are not retained in any database.
5. Digital Swabs – Members shall read the consent statement provided as part of the DNA collection kit before collecting digital swabs. It is the responsibility of officers collecting digital swabs to book the swabs.
6. Penile Swabs – See current Department policy for specific procedure.
7. Clothing – A victim’s or suspect’s clothing may be essential evidence. Paramedics or medical personnel may remove clothing at the scene, in the ambulance, or at the hospital. When CSI is not responding and if feasible, officers shall take custody of this clothing, transport it back to the station in paper bags and allow to air dry before booking. If especially bloody clothing is being stored temporarily at a District Station prior to booking or for CSI to seize, it must be stored in such a way to protect from contamination.
8. Video Evidence – Video is a critical piece of evidence in many cases. Whenever possible, members should canvas scenes for possible video cameras. This canvas should include not only the immediate incident scene, but also cameras which may have captured the direction of travel of involved parties, possible alternate angles, or which may have captured the involved parties prior to or after an incident. When cameras are located, their presence should be noted in the incident report. If members can view the video footage, they should note the time shown by the recording system (“System Clock”) so that the footage can be retrieved by Multimedia Evidence Unit (MEU), or an officer trained in video retrieval. If a member is provided a recording of video evidence on digital media, this recording must be booked as evidence and listed in the report. If there is a chance that video evidence may be overwritten or there will be a delay in retrieving the evidence, members should consider recording the video evidence using their department issued cell phone and/or a Body Worn Camera.
9. Digital Evidence – When members determine that digital media at a scene may have evidentiary value, they shall take necessary steps to ensure the evidence is protected from damage and chain of custody is maintained. Data and power cables should be collected and booked in the same package as the device. To preserve evidence, members should not turn mobile devices off and if possible, they should take steps necessary to prevent it from communicating with all networks and devices (for example, disable Bluetooth, Wi-Fi, and cellular connections). In addition, if available, use a Faraday bag to preserve the mobile device and evidence. Wet or submerged items of digital evidence should be preserved in the liquid it was found in. Transport it in a plastic container and seek immediate guidance from the MEU. If members have questions or concerns regarding digital evidence, they can contact MEU at (415) 678-3597 during business hours, or through the Department Operations Center at (415) 553-1071 after hours and on weekends.

I. Packaging Evidence – (See DGO 6.15, Property Processing and DGO 9.03, Mandatory Blood Tests for Drivers Under the Influence)

General Guidelines – Members shall ensure that all contents are listed on the exterior of their packaging. This is generally satisfied by the attachment of Evidence OnQ barcode labels or equivalent. Safely package sharp, fragile, or hazardous (including biohazardous) materials and label them as such. Members shall mark the container into which those items are placed with their initials or star number, description of the evidence, and the incident number assigned to the case.

Should any questions arise as to the correct and safe procedures for the packaging of any physical evidence, contact the CSI unit.

1. Firearms – CSI routinely processes firearms for fingerprints and DNA. Members recovering firearms should take safety precautions to protect and preserve possible trace evidence on firearms. Generally, CSI will process a firearm for fingerprints and DNA only when the firearm is not found on a suspect’s person although exceptions can be made at the discretion of the duty CSI Team Leader. If CSI will be seizing the firearm for processing, DO NOT UNLOAD, REMOVE MAGAZINE OR BOOK. Do not mark the firearm. Contact CSI Unit for pick-up.

   Firearms may be packaged and booked by an officer when no CSI processing is required. Wear fresh latex or nitrile gloves and use caution while handling a loaded firearm. Unload firearms before packaging and booking. Book firearm and ammunition in a firearm envelope, separately from other evidence. Place unloaded ammunition in a smaller separate envelope within the firearm envelope. Fired cartridge casings should not be booked with firearms or live ammunition. Never BOOK A LOADED FIREARM; see department notices and NIBIN protocols addressing procedures for handling firearms and related evidence.

2. Money – Package money (U.S. and foreign currency and coin) in a green "Money for Identification" envelope separate from all other evidence or property with the amounts and totals written out on the appropriate lines. Label the envelopes prior to inserting the currency.
3. Biological Evidence – Biological evidence requires careful handling, not only to preserve evidence but also to protect members from possible contamination. It is imperative that members wear fresh latex or nitrile gloves when handling any biological evidence. Dry biological evidence does not require freezing to maintain the integrity of DNA evidence. All such evidence shall now be booked with only "BIOHAZARD" labels, as appropriate, and shall be stored at monitored room temperature in Property Control Division. Members will follow the subsequent procedures when handling or booking the following types of biological evidence.
   procedures when handling or booking the following types of biological evidence.
   1. Swabs - All swabs, regardless of source, shall be labeled and placed within the designated `Tyvek' envelopes included in the swab kits. These shall be booked in an evidence envelope as normal.
       
   2. Sexual Assault Evidence - Bed sheets, blankets, towels, clothing, or other evidence from the crime scene containing possible DNA evidence shall be packaged and booked separately in clean property bags. Attach a "BIOHAZARD" label to the bag. Air-dry prior to packaging if necessary. A CSI response is not required for evidence packaging. 

   3. Condoms - Officers shall use fresh latex or nitrile gloves to gather each used condom and each used condom wrapper. Officers shall also use sterile plastic cups (commonly used to collect urine samples) to hold each used condom. Condom wrappers can be packaged in an unused coin envelope or a similar type of unused envelope. The sterile cups are readily available at the Department's Property Control Division, and Commanding Officers should instruct their facilities managers to stock their stations or units. When collecting condoms or condom wrappers, members shall follow the following procedure: 

      1. With fresh gloved hands, the officer can break the sterile cup's seal, remove the cap, pick up the condom by its base/rim, place it in the cup and replace the cap.
      2. When collecting multiple condoms, officers shall handle each condom separately using fresh gloves every time and place each condom in a separate cup.
      3. These shall be booked in separate evidence envelopes and shall have a "FREEZER" label attached, per the "liquid sample" exception.
      4. With fresh gloved hands, the officer can pick up the condom wrapper and place it in a coin envelope. The wrapper shall be booked in a separate evidence envelope and does not need to be marked "FREEZER."

      Officers assigned to the Airport Bureau will follow the San Mateo County Sheriffs protocol for Booking of Biological Evidence.

4. Questioned Documents – Documents can be treated to reveal latent prints, or indented writing, so always wear a fresh pair of latex or nitrile gloves when handling papers. When handling questioned documents, follow these rules:
   1. Do not allow the suspect to handle the questioned document.
   2. Preserve the questioned document for latent fingerprints and/or indented writing.
   3. Do not write on or mark the document in any way.
   4. Store and transport the document in an envelope. Use an envelope that is large enough to allow the questioned document to be stored in it without the need to make any new folds in the document. In order to prevent adding indentions to the document, write the description of the evidence on the storage envelope before placing the questioned document inside.
   5. Keep a record of each document, including the date, place, and person from whom it was obtained, and include this information in your incident report.
   6. Keep documents away from excessive heat, light, or moisture.
   7. Never attempt to reconstruct a torn or damaged document.
5. Flammables – Contact the Arson Task Force or DOC for assistance. (See DGO 6.15, Property Processing, Flammable Substances)
    
6. Destructive Devices – Contact Explosives Ordnance Disposal (EOD) or DOC. (See DGO 6.15, Property Processing and DGO 8.08, Bomb Threats, Clandestine Laboratories, Destructive Devices, Explosions and Fireworks) 

7. Narcotics/Controlled Substances – Whenever members handle any possible narcotic, even when the suspected narcotic is inside packaging, members shall wear fresh latex or nitrile gloves to protect themselves from potential exposure. Place the item of evidence in an envelope with a narcotics sticker label or plastic bag. Members shall place their initials and star number on the envelope or plastic bag. Place the envelope or plastic bag in an "Analyzed Evidence" envelope with the narcotics sticker label. Seal the flap, write the member’s initials and star number, and then seal with transparent tape. Hand carry the "Analyzed Evidence" envelope to a designated narcotics drop and place it inside. If the item is too large to be placed in the drop (marijuana plants, kilos, etc.), contact the DOC or the Crime Lab. (See DGO 6.15, Property Processing)

   When a container holding narcotics needs to be fingerprinted, book the container to be fingerprinted separately from the narcotics evidence. Do not mark the item(s) to be printed prior to processing for fingerprints.

8. Possibly Hazardous Evidence – If unknown liquids, fireworks, acids, or corrosives, need to be booked as evidence, contact CSI unit or the DOC for assistance or follow the direction of the Fire Department, as applicable. (See DGO 6.15, Property Processing and DGO 8.07, Hazardous Material Incidents)

J. 11550 HEALTH AND SAFETY CODE VIOLATIONS – (See DM-3, Driving Under the Influence of Alcohol and DGO 6.15, Property Processing)

K. Requesting Crime Laboratory Analysis – The Crime Laboratory is accredited by the American Association for Laboratory Accreditation (A2LA) in the following disciplines:

1. Nuclear DNA Analysis and Body Fluid Identification
2. Trace Evidence - Gunshot Residue Trace Evidence
3. Firearms and Tool Marks Examination
4. Distance Determination
5. Physical Match
6. Serial Number Restoration 

7. Footwear Examination

   The investigator assigned to the follow-up investigation shall request Crime Laboratory analysis. Submit such requests on the Request for Laboratory Examination form (SFPD 64). Email this form to [email protected].

L. Requesting Fingerprint Processing, Comparison and Examination for Indented Writing – Fingerprint processing is normally requested by the investigator assigned to the follow-up investigation. Occasionally, patrol officers doing the preliminary investigation may request, or be directed by the investigator to request, fingerprint processing of physical evidence. To request such analysis, complete the Latent Fingerprint Request form (SFPD 235D) and forward the form to the CSI unit. Book the evidence into Property Control in the usual manner. When you make a request for a CSI unit to respond to a station or detail to process evidence for fingerprints, do not mark the item(s) to be printed. Place the item(s) in the designated CSI locker or secure location. Complete and provide a Property for Identification envelope also. When CSI is through processing the item(s), the booking of the item(s) can be completed. Request that evidence be examined for indented writing before it is chemically processed for fingerprints.

M. Requesting Digital Evidence & Forensic Processing – Members needing the forensic processing of computers, mobile devices or other digital media should complete a SFPD Forensic Services Division Examination Request form (SFPD 64A). Investigators are encouraged to discuss their case with the forensic examiners so that the examiners know what specific digital evidence they need to be alert for. Members shall collect proprietary power cables and ancillary devices (with the exception of monitors, keyboards and mice) with the digital evidence to be examined, whenever possible. If digital evidence will be forensically examined by the MEU, members should not manipulate or search the device, with the exception of the above-listed preservation steps.

N. DUI Blood and Urine Specimens – (See DM-3, Driving Under the Influence of Alcohol and DGO 9.03, Mandatory Blood Tests for Drivers Under the Influence) 

O. Blood and Urine Specimens Related to Homicides or Other Serious Cases – The investigating officer or investigative section handling the investigation shall collect blood and urine specimens related to death or other serious cases. Members shall hand deliver these specimens to the Toxicology Laboratory, located in the Medical Examiner's Office. 

P. Blood Samples Drawn from Victims or Suspects in Death or Impending Death Cases (First Blood Drawn Specimens) – It is the responsibility of the investigator assigned to the case to arrange for these blood samples to be collected from medical personnel as soon as possible after the samples are drawn. Since CSI personnel will normally be handling bloodstains from the scene in these cases, they shall not be assigned to collect the First Blood Drawn specimens to prevent any possible contamination of the bloodstains from the scene.

References 
DGO 6.03, Underwater Diving Operations 
DGO 6.15, Property Processing 
DGO 8.01, Major and Critical Incident Evaluation and Notification 
DGO 8.07, Hazardous Materials Incident 
DGO 8.08, Bomb Threats, Clandestine Laboratories, Destructive Devices, Explosions and Fireworks 
DGO 8.11, Investigation of Officer Involved Shootings and Discharges 
DGO 9.03, Mandatory Blood Tests for Drivers Under the Influence DM-3, Driving Under the Influence of Alcohol 
Department Notices regarding Gunshot Residue Collection 
Department Notices regarding Procedures for Handling Firearms, Fired Cartridge Casings with Evidentiary Value and NIBIN Protocols