12 Administrative Guidelines for Crime Scene Searches
Written by John Louis Larsen   


This article appears in the September-October 2021 issue of Evidence Technology Magazine.
You can view that full issue here.

THE 12-STEP GUIDELINES in this article are intended as an effective monitoring tool for law enforcement administrators. This process can be utilized on any case, and whenever a department is working in conjunction with a task force.

The approach was initially developed at the FBI National Academy (Moreau ca. 1980) by managerial and line supervisors in the law enforcement community and was later adopted in the early 1990s by FBI Special Agents while establishing the Evidence Response Team (ERT). The 12-step process became the backbone of the program, having been taught and adopted by police agencies throughout the U.S. and the world.

The author has modified the Standard ERT 12-Step Process. The FBI ERT process’s first step is Preparation, which ensures that the team leader and members have the appropriate legal authority (i.e. search warrant, signed consent to search, etc.) and that the team has the appropriate personal protective equipment (PPE) to function safely within the scene environment. At the conclusion of the article, I have included the FBI’s 2019 ERT Team Leader Conference 12-Step Process in an abbreviated format.

The 12-Step Guidelines (referred to as "guidelines" for the balance of this article) should be incorporated and applied to all searches, both criminal and accidental (i.e. vehicle crashes, trip and fall, etc.). An administrator and/or investigator in the field can use the guidelines to effectively direct and document both the simplest and the most complicated searches. It is important that once the guidelines are adopted as a standard operational procedure, they should be routinely applied regardless of the size and complexity of the scene. This documentation will provide a framework and foundation for the use of these guidelines.

The 12-Step Guidelines:

  1. Approach scene
  2. Secure and protect
  3. Conduct preliminary survey
  4. Document through narrative description
  5. Photograph scene
  6. Sketch scene
  7. Evaluate scene
  8. Evaluate evidence
  9. Conduct search
  10. Collect, record, mark, and preserve evidence
  11. Conduct final survey
  12. Release the scene

The guidelines provide the administrator with a simple tool to maintain control, assist the officers in the field in a timely manner, evaluate the quality of the evidence, assist in determining the type of evidence being gathered, as well as ensure the safety of the officers, civilians, and other governmental agencies assisting in the investigation. If one of the steps is skipped, it should set off alarms. It is better to backtrack and repair immediately any missed step. A step not completed will eventually be discovered by the prosecutor or defense. The underlying nature of crime scene processing is directed at unearthing the facts, safeguarding the physical evidence, and presenting these facts in court.

A series of actions accompany each of the 12 guidelines.

Step 1. Approach

The first responder lays the foundation as the state's initial representative on the scene. The officer is the first professionally trained observer positioned to document the scene before it is altered – for example, by removal of the decedent in a homicide case. The primary approach for the first responder is not only securing and protecting the scene but also assessing the threat level, defining the boundaries of the scene, assisting victim(s), identifying potential witnesses, and determining how the subject entered and exited the scene. It is incumbent upon the lead investigator/search team leader/officer-in-charge (OIC) to consult with the first-responding officer. This consultation is all part of the first step. The OIC needs to have a clear picture of what elements make up the incident scene and if the scene has been disturbed or compromised.

Documented evidence of the first responder consists of their notes, rough sketches, and photographs taken with their cellphone or department-assigned camera. (If a cellphone is used, it should be recovered as evidence.)

The issue of contamination frequently arises within Step 1. For example: At a homicide, an officer might move a weapon within the scene before it is documented (usually photographed and/or measured and sketched in place). This simple action may be the entry point for a defense attorney to mount an attack against the state. In the case People of Wisconsin v. Kayle Alan Fleischauer, Case No. 18CF255, which was a first-degree murder trial, a pistol associated with the shooting death of Fleischauer's son was moved by officers twice without proper documentation within the scene. This created a muddled situation in trial for the prosecution.

I want to address other common contamination and safety issues pertaining to Step 1, such as in the case of People of Wisconsin v. Miguel A.F. Navarro, Case No. 2018CF156, which dealt with the August 5, 2019 homicide of Israel Valles-Flores at the hands of Miguel Navarro. Navarro's weapon was a circular saw. Navarro and Flores were re-roofing a house when Navarro killed Flores. The scene of the crime started at the peak of the roof on the second story and descended to an attached garage roof on the first floor. Local police and county sheriff deputies responded to the scene. The sheriff's department took over control of the scene, to include processing and overall investigation. On December 5, 2019, Navarro pleaded guilty to one count of reckless homicide in Pierce County Circuit Court (Gray 2019). The police and sheriff's investigator perceived this case as a slam-dunk, since the homicide was done in broad daylight in front of two witnesses. The scene was photographed by the sheriff's lead investigator.


Figure 1. Photos from the scene where Israel Valles-Flores was killed with a circular saw. Note the deceased body on the attached garage roof.

The physical evidence was overwhelming, but it could have turned disastrous if any number of evidentiary exhibits had been found to be contaminated or if the collection was improperly done, especially in the area of fingerprints and DNA. Defense attorneys will utilize distractive issues to pull the jury away from the state's theory of the case. In the photographs below, we can see a number of potential issues that could be used to skew the state's narrative. In the crime scene photographs below, investigators are observed in the scene not wearing protective shoe covers or protective clothing. Administrators should try and remember the “CSI effect” we are dealing with when presenting a case to a jury. In this series of photographs, we observe sheriff’s detectives photographing and processing the scene in their summer uniforms and mismatched footwear.

Figure 2. Photograph of sheriff's detectives investigating the roof-top scene in mismatched footwear.

If the officers are not wearing protective booties (covers) within the scene, the possibility of generating misleading footwear impressions increases. If it is impractical for officers to wear shoe covers, it is suggested that exemplars of their soles be taken. This would be done immediately after the search. Shoe tread wear patterns are unique like fingerprints. They can easily be altered by an officer accidentally walking through them – so it becomes important to document their shoe tread impressions as soon after the search as possible. If SWAT is actively engaged within the scene, impressions should be recovered before they are released from the scene. Once the search team is released, it can be difficult to collect the footwear impressions in a timely manner due to other ongoing responsibilities of the officers. In that interim period, their footwear impressions are being altered in the course of their daily activity.

Protective gowning (PPE) should be mandatory in all violent scenes not only to prevent officers from contaminating the scene, but also, more importantly, to cut down the chance of bio-hazardous and trace evidence being transferred to them, their patrol vehicles, the department, and the officers’ homes (Masters 2002). The department has a “responsibility for developing programs to protect workers. Based upon reviews of the pertinent data, 29 CFR Par 1910 states that certain employees (crime scene technicians and investigator, added by writer) face a significant health risk as the result of occupational exposure to blood and other potentially infectious materials because they may contain bloodborne pathogens…" (Masters 2002).

Two issues immediately come into question concerning officer protection and collection of evidence. In the case referenced above, the officers are working in an extremely bloody scene. They are not wearing protective clothing, face shields, eye protection, or shoe covers. OSHA standards come into play within violent crime scene environments, especially when dealing with bloodborne pathogens (Masters 2002). Their departments have placed them in an unsafe position in which they can be contaminated and/or be instruments of contamination (by bloodborne bio-pathogens associated with the victim whose medical history is unknown). The department could open itself to civil suit and workers’ compensation claims. The officers working such scenes who have not been provided with personal safety equipment may become carriers and become infected. This leaves their departments vulnerable to civil suit.

In our case above, the officers processing the scene appear to have worn only a single set of evidence gloves throughout the processing of this incident. The likelihood of cross-contamination rises the longer they are in this scene without the proper safety barriers to shield them, as well as the evidence they are attempting to recover. The more they process the scene with only the one protective glove layer, the more items within the scene are cross-contaminated. The officers unintentionally might be transferring trace and biological evidence when collecting and packaging evidence. This transference of trace and biological evidence can occur between subject, victim, and collector, which could significantly damage a case.

The outside of packaged items can also become a carrier of biological and trace evidence. These items can be compared to a time bomb. Contaminates are invisible, and their very nature is transitory. Each person who handles and transports the contaminated item becomes a potential carrier (indirect transfer) of trace and bio evidence. This is especially true of evidence custodians who, in their normal course of business, will come in direct contact with the packaged evidence and, in some instances, repackage items (e.g., wet clothing removed from original package and placed in a drying cabinet).

Figure 3 below is taken from crime scene photographs.

Figure 3. A series of photographs taken from a rooftop crime scene.

Step 2. Secure and Protect

“Secure and protect” goes beyond posting an officer at the entrance to the scene. This step establishes how to define the station where crime scene personnel enter and exit the scene. One way of documenting this step is through an Entry/Exit Log. The log will aid in identifying who, when (time in and out), and why (reason for entry). It should be common practice used at all scenes. An officer should be assigned this task of maintaining the Entry/Exit Log. The question arises whether the officer stationed at the entry access point will be responsible for maintaining and filling in all entries on the log. It is important to be consistent. For purposes of court, the officer maintaining complete control of the log makes it much easier for the assistant state’s attorney to determine who was present within the scene and what their responsibilities were.

It falls on the OIC to define the perimeters of the scene. In a homicide scene there may be more than just the primary scene of activity, especially if the perpetrator forced entry, left blood trails, or if multiple scenes exist within one scene. For example, when violent action has occurred throughout a structure's perimeter, a secondary perimeter may need to be defined in order to allow search-team personnel to stage the area as well as establish a neutral zone to keep out civilians and press. In the Flores crime scene above, the roof and rear garage entrance areas were extensions of the primary roof scene. The murder weapon (circular saw) was discovered near the rear garage entrance as seen in the photographs taken by Pierce County Sheriff's Investigator below.

Figure 4. Crime scene photos show that a circular saw, used as a murder weapon, was found near the rear garage entrance.


If it cannot be shown that the scene was secure and continuously protected throughout the search, then the evidence recovered will, in all likelihood, be thrown out during discovery.

Step 3. Preliminary Survey & Step 4. Narrative

The preliminary survey is conducted by the OIC or scene manager before the search is executed. It reflects the search team's initial observations. The preliminary survey is basically a walkthrough of the scene by the OIC to provide an analysis covering the makeup of the scene, compartmentalization of items throughout the scene (note those items observed within the scene common to the location), physical evidence (e.g., weapons, etc.), bloodstain patterns (e.g., bloody footwear impression, blood trail, etc.), environmental conditions (e.g., light), and safety issues (e.g., structural considerations as seen in the roof photo above). This step is strictly preparatory to the actual search.

Based on what has been observed, the OIC will generate a narrative which can be handwritten or electronically recorded. Special Agent Douglas Seccombe, FBI Chicago Division senior ERT leader, stated the Evidence Response Team Unit in Quantico, Virginia, now encourages the preliminary survey be done by the team leader as well as the photographer before the cover sheet (photo identification placard / gray card) has already been taken as the first photograph. The rationale is that two initial observers are better than one. During the walkthrough, the OIC and photographer may see certain things to photograph that may be beneficial to the team briefing and to investigators –such as potential actionable leads.

The narrative provides a foundation for the OIC to establish a good working plan for the search. The OIC narrative and the first officer’s notes aid in developing a working theory of the case that is invaluable to the state’s attorney. They provide a foundation to establish reasoning behind the processing of the scene.

Step 5. Photograph Scene

Photographing the crime scene is not a guideline issue but rather one of protocol. It is incumbent that the scene be documented in its entirety. Three different types of photographs are taken. The first set of photographs are for orientation (overall); the second set of photographs are midrange photographs with a focus on a specific subject of interest within the scene; and the third set of photographs developed off the midrange photographs clearly identify detail. In the third set, a micro or macro lens may be used to capture precise detail, such as latent fingerprint impressions. The photographs should provide a foundation or outline to build the story of the event. Scene photographs can assist in clarifying and compartmentalizing the actions within the scene (e.g., bloodstain evidence interpretation/analysis).

Crime and incident scene photographs are usually taken in chronological order starting with a face sheet (identification placard/gray card) showing case number, date, location, and photographer. “A crime/incident scene poorly photographed will only assist in distorting the facts and provide the defense counsel with an area that can be probed in court” (Larsen 2011).

Step 6. Sketch Scene

A rough sketch is an important protocol step as well as a foundational process. The crime scene sketch provides the OIC with a literal outline of what has to be searched and documented. The orientation of the sketch is in keeping with the photographer’s overall perspective. Photographs do not replace scene sketches. Multiple sketches may be needed based on the depth and nature of the scene. For example, the scene may cover a large geographic area as in the Navarro case (see diagram below). Four diagrams were generated to show the overall and specific search area as well as the items located in each area.

Figure 5. A scaled scene diagram of the Navarro case, as created by the Wisconsin State Patrol.

In general, a sketch or diagram demonstrates the relationship between evidentiary items. The most important facet is that it provides an overall view and directional orientation and can be used in witness interviews, grand jury, and at trial. “A rough crime scene sketch should be executed with the expectation that the rough sketch can be converted at a later date for presentation at grand jury or in court” (Larsen 2011). At a minimum, the sketch should include: specific location, date, case identifier, preparer, scale or scale disclaimer, compass orientation, evidence/specific objects, measurements if needed, a key, and a legend. The sketch will allow the assistant state’s attorney quick and accurate information about the scene. The sketch allows for a clear understanding of what and where an item of interest is within the scene. A good rough sketch can assist the OIC and directly aids in the navigation of the scene. I like to view it as a road map highlighting points of interest to be developed in the search and general investigation.

Step 7. Evaluation of the Scene (Environmental)

Within this step, the OIC is concerned with the overall physical makeup of the scene. This step is ongoing throughout the search. A number of issues may have to be resolved before a search can be executed: scene safety, power and appropriate light, engineering point of view (e.g., removal of debris and bracing of the structure), contamination with blood, and other bio-contaminants throughout. In most of our violent crime scenes, the bio-contaminant issue is defined to a specific area. Even though there may be limited biological exposure to officers processing the scene, it does not waive Federal Safety Standards 29CFR1910 (Code of Federal Regulations) which are regulated by OSHA. These regulations require that if an officer is injured or taken sick as a result of a search due to improper or insufficient issuance of protective gear, nitrile gloves, face masks (shields), or protective gowns, then the department opens itself to civil and federal prosecution (i.e., 29 CFR 1910.1030, “Bloodborne Pathogens”).

If officers are working with materials that have excessive blood contamination, then wearing double nitrile gloves will allow the officer to have a clean protective layer under the secondary glove which may have bio-contaminants on it. According to Masters, “The requirements under this standard are very specific to biological materials. All employers are required to develop safety policies in line with the regulation.”

In this guideline step, the OIC may determine that search members will need certain equipment to be able to safely navigate the scene, as seen in Figure 2, where the fire department secured ladders on the roof of a house so that search team members could safely traverse the roof to photograph and take blood swabs.

Step 8. Evaluation of Evidence

This step is ongoing and starts from the very beginning when the OIC walks into the scene. The investigative process starts from the call out to the scene and ends with presentation (testimony) at trial. The OIC evaluates the scene environment and the evidence with an eye to establishing what evidence needs to be collected or field-processed first. There is a hierarchy of evidence, starting with trace evidence working from the most transient to the bulkiest items. Trace evidence has a way of literally walking away or being obliterated by well-intentioned support units such as first responders, paramedics, and firefighters. In a search environment, the lead investigator closely monitors both Steps 7 and 8.

In the Navarro case, the OIC was aware of a late afternoon summer thunderstorm threatening the crime scene. There was a footwear impression in blood on the garage roof near the body that was preserved through photography even though the deceased body lay near it on the roof. (The coroner, with the assistance of the fire service, removed the body before the storm). The OIC made a judgment call to preserve and protect the bloody footwear impression which could not be cast or recovered in any other manner. Consequently, the OIC did not lose sensitive identifying evidence that could have been washed off the roof and surrounding area. This was true of many other physical items collected before the storm. In this situation, the investigators could have also cut the area out for submission to the laboratory. (This is one of those moments OIC could have called the state laboratory and asked for their recommendation.)

Within Steps 7 and 8, the OIC can detail circumstances surrounding the recovery of specific evidentiary items. Providing special details surrounding the discovery needs, as well as special documentation, allows not only the officer testifying at trial to provide greater detail to the court and jury, but also gives the state’s attorney a larger brush with which to paint a more detailed story. Prosecutors like it when an officer provides detail to the jury. For example, one of my associates did a field test of the phenolphthalein to prove it was working before using it on possible bloodstains. That simple procedure undercut the defense. I have been questioned in court on false positives. If the defense can show that the CSI did not check the presumptive test prior to testing the bloodstain, the defense can argue that the result was a false positive.

Step 9. Conduct Search

Over the last 38 years, I have worked with some law enforcement administrators at the local, state, and federal levels who have thought that too much time, manpower, and equipment has been consumed in the processing and post documentation of search scenes. I have interpreted this to mean too much money has been spent for too little result. To me, this attitude reflects the notion that a search is a relatively simple procedure. As a practitioner and police instructor, experience has taught me that a well-done search is a relatively simple matter if properly executed in a systematic manner, with all personal focus on the capture of physical evidence. With this method, a successful outcome in criminal and civil litigation is more likely.

The search should be done systematically with searchers assigned to specific areas with defined responsibilities and an understanding of the search protocols. I have seen officers and agents who are well-intentioned destroy a search site in an attempt to recover weapons, money, and drugs — resulting in the scene being tossed. (When law enforcement personnel swarm a scene on “an officer needs assistance” call, it is understandable that the scene may be altered by their presence. The minute the emergency is resolved, it should be understood that the scene be cleared, and only officers responsible for documenting the incident remain on station.

Evidence recovery and documentation of evidence has become standardized practice in which a search will locate a possible evidentiary item. Once located, the searcher informs the OIC. The OIC or designated assistant will make sure the item has been photographed in detail and the item is assigned a numerical or alphabetical tent marker. In turn, the item is again photographed (orientation, midrange, and close-up photographs). Then the item can be recovered, packaged, sealed with tamperproof tape, and provided with an identification number. Initials of the individual who recovered the item and the team leader should be written across the seal with the date and case number.

Evidence and missteps that can cause problems before and after packaging are:

  • Footwear and garments need to be individually packaged (especially footwear)
  • Clothing that is damp should be removed from the original package and repackaged once it is dried. The original package should accompany the item.
  • Trace evidence (e.g. hairs and fibers) need to be packaged within pharmacy folds or containers that do not allow the items to escape (e.g., vacuum-sealed container).
  • Weapons (e.g. pistol or revolver, made safe) and ammunition should be packaged separately. In the case of a revolver, be sure to remove and document each fired and unfired cartridge casing and its position within the cylinder. For semi-automatic pistols, note the position of the slide at the time the pistol was discovered, the number of rounds in the magazine, and whether there was a live round in the chamber.
  • DNA swabs must be properly packaged.

Another critical issue that continually presents itself is the movement and removal of evidentiary items within the scene before documentation has been completed. From my experience, firearms are the most common kind of evidence to be moved or removed from a scene. I have had cases such as People of Wisconsin v. Fayle Alan Fleischauer (2018 murder case) where the first-responding officer, after viewing the deceased on the floor, located a pistol on the hallway floor adjacent to the body. The officer placed the pistol on top of the refrigerator in the kitchen before it was photographed and documented. A supervisor removed the pistol from the top of the refrigerator, rendered it safe, and placed it on the kitchen island, which happened to be part of the shooting incident. The first-responding officer did properly file a supplemental report outlining his actions, but no one was able to identify the actual spot where it was initially observed. This sort of incident occurs frequently to the chagrin of scene supervisors. Once the OIC becomes aware of the situation, some form of photographic and written documentation needs to be generated (e.g., evidence recovery logs, sketches, and entries made in the OIC narrative). The responding officer’s supplemental report should accompany the item with the chain of custody form to establish the item’s pedigree. This is an area where doubt can be cast on the professionalism of the officers as well as the search process. It creates a credibility issue in the eyes of the court and the jury.

Step 10. Collect, Record, Mark, and Preserve Evidence (Chain of Custody)

Collecting, recording, marking, and preserving the evidence can be a time consuming activity. These four elements need to be done in detail. Under Step 9, the searchers identify the items to be collected. In Step 10, the items are physically collected. It is suggested that the collection of evidentiary items be witnessed by at least two officers, especially when it comes to the collection of latent fingerprint impression and DNA swabs. The question frequently arises with field supervisors about the need for these steps. Why don’t they just bag-and-tag the items? The answer lies with the fact that all this work is preparatory for the future trial. The more detailed, the easier it becomes for the lead investigator to testify to the physical facts surrounding the incident. The process is designed to be open-ended because it may take years before the evidence is presented at trial (e.g., homicide case).

The evidence needs to be recorded (documented). One form of documentation is to use an Evidence Recovery Log. An Evidence Recovery Log is a document organized into columns with clear headers (Figure 6). Example of an Evidence Recovery Log below. This type of log can be expanded and altered to the needs of the department.


Figure 6. Example of an Evidence Recovery Log.

The header includes:

  • Case number
  • Date of search
  • Date and time evidence was recovered*
  • Location
  • Personnel conducting the actual search
  • Log keeper(s)

*Note: The time that evidence was recovered sometimes becomes an issue in court raised by the defense. A way of circumventing the time issue is to have all items identified as being collected at the termination of the search. This simplifies the testimony and removes unnecessary discussion on when an item was recovered. It also provides a window for items recovered and thought not to be germane to the case to be returned to the scene — such as a stolen vehicle search involving a child kidnapping where clothing is recovered and investigators determine the clothing is not that of child who was kidnapped but belonged to the children of the owner of the stolen vehicle.

Columns include:

  • Item number – Specific identification marker, barcodes, etc.
  • Description of item – e.g. “Sig Sauer 220 pistol” This area can cause problems if the item is described incorrectly. Sometimes it’s better to simply say revolver, pistol, etc.
  • Where found – e.g. “Master bedroom / northeast corner / under end table”
  • Recovered by / Observed by – Include initials of both parties (usually OIC initials are on all items), thereby allowing either party to testify
  • Photographs – Within this heading are the photo numbers associated with the item seized. This information is obtained directly from the photographer and photo log keeper. E.g., “Photo #10, 12, 14 (orientation photos), 56, 57 (midrange)”
  • Marking – Marking means the item was directly or indirectly marked for identification. This consists of the initials of the recovering agent and the date. Direct marking occurs when the mark is placed on the item itself (e.g., a pistol inside the grip, with the finder's initials or some other identification mark). If something is indirectly marked, it has not been marked but rather some alternate form is used to identify it – for example, use of a tag tied onto the item with all the identifying information. Sometimes it is referred to within its evidentiary package. (The direct marking of evidence is becoming less frequent due to the expanded use of DNA evidence.)
  • Miscellaneous comments – Anything of interest associated with the item recovered, such as in our example above of the pistol. You want to note that you observed that the slide was locked back, the serial number, and so forth.

The Evidence Recovery Log is a detailed summary sheet. Over time, it can act as a historic document. It’s an effective tool for administrators as well as the assistant state’s attorneys to quickly use to become familiar with the physical elements within the case. The Evidence Recovery Log can be modified to meet the needs of any department or specific requirements for any search or searches. For example, in the Traci Todd homicide case, the Chicago FBI ERT conducted 13 separate searches over a three-month period before Kevin Williams was arrested for the murder of his girlfriend, Traci Todd. Evidence Recovery Logs act as an outline and tracking tool not only for detectives but also for the ASA.

Chain of custody preserves and documents the evidence for the court, as well as a history of the item from acquisition to court to disposition.

Step 11. Conduct Final Survey

At the conclusion of the search, the photographer should do a series of overall photographs of the entire scene in conjunction with the OIC and an assistant (a second pair of eyes) as they conduct a walkthrough of the entire scene. Photographs of the overall scene at the end of the search have saved me and my agency (FBI) from being sued in federal court. In this particular case, a suspect in the UNABOM case claimed that my associate and I had damaged his Corvette in a search. The case was thrown out of court because the final survey photographs proved to the court that the complainant had misrepresented his claim.

The walkthrough is done for the following reasons: 1) to verify that all the evidence within the scene has been recovered and collected, 2) to make sure that no search equipment and exhibits have been left behind, and 3) to make sure all special search analysis has been completed (e.g., bloodstain analysis). The final survey provides a great opportunity for the entire team to review and make sure they collected everything, such as known samples, before they release the scene.

Step 12. Release Scene

The scene is to be released only after the final survey has been completed and the search team has had a chance to discuss what evidence has been found and recovered. If a team member perceives that some item of evidence has been overlooked, it gives the OIC an avenue to stop the closing process and expand the search to its logical completion. If the search is declared complete, and all items of evidence have been accounted for and removed, the site can be secured. It is important to document (photograph or video) what steps were taken to secure the scene, especially if it is private property.

The following three items need to be documented on the closing search documents:

  • Time and date of release of the scene
  • To whom was the scene released
  • How the scene was secured

If there is no one identified to whom the scene should be released, then a copy of the inventory with a business card can be left in an observable place. In the case of a search based on a search warrant, a copy of the warrant and inventory of the items seized can be placed in a prominent location at the site. This is a federal rule. I know many of the states do not have this requirement – so I would recommend that investigators check with their local state's attorney or district attorney. In either case, I would recommend photographic documentation of the process.


Forensic evidence serves as the foundation that will support the theory of the crime. The 12-step guidelines provide law enforcement administrators with a tool to monitor and evaluate the effectiveness of their agency’s searches. If a step has been omitted or is faulty, it will give administrators a way to provide guidance and direction. If a department adopts the 12 steps as their standard operating procedures (SOPs), it will act as an insulator against civil liberties lawsuits. The effect created by this SOP will be overall improved searches and recoveries. When the physical evidence is presented at trial, it provides the foundation upon which each officer will build. The judge and jury will see a systematic gathering of evidence that was objectively collected and is, for the most part, free of bias. The 12 steps provide an effective barrier by defusing the defense’s attack in search of reasonable doubt by way of destroying and clouding the facts on how the evidence was recovered.

2019 FBI ERT Team Leader Conference 12-Step Process/Guidelines (summarized)

  1. Preparation – Legal authority is confirmed, line up SME’s if necessary, make team assignments
  2. Approach Scene – Establish control, ID safety hazards.
  3. Secure and Protect Scene – Establish inner and outer perimeters.
  4. Initiate Preliminary Survey – Establish entry/exit, protect transient evidence, determine equipment needs such as drones and 3D scanners, enter with photographer to take initial entry photographs for team and investigators.
  5. Develop Evidence Collection Plan – Determine evidence types most likely to be encountered, prioritize transient evidence, report any actionable intelligence.
  6. Document Search Activity – Admin Worksheet and Log, Evidence and Photo Logs, Narrative, etc. Document results of presumptive tests.
  7. Depict Scene Photographically
  8. Prepare Diagram/Sketch
  9. Conduct Detailed Search
  10. Record and Collect Physical Evidence – Complete all documentation before leaving scene.
  11. Conduct Final Survey – Meet with team and discuss if everything was done before releasing the scene; e.g., were known samples collected?
  12. Release Scene

The author would like to thank FBI Special Agent Douglas Seccombe Senior ERT Team Leader of the Chicago Division for his assistance in writing this article.

About the Author

John Louis Larsen served as a Special Agent with the FBI for 22 years and was one the founders of the FBI’s Evidence Response Team (ERT) program. His last duty assignment was with the FBI’s Chicago Division as senior ERT leader. Larsen currently is president of Larsen Forensics & Associates. He has worked as an investigator for the Special Prosecutor’s Office of Cook County and was a senior forensics consultant with Quest Consultants International, Ltd.; a sworn officer with the Office of the Special Prosecutor of Cook County (Illinois); and a training instructor for Sirchie Laboratories in use of the Reflective Ultraviolet Imaging System (RUVIS). He is also an adjunct instructor for the Homeland Security Training Institute at the Suburban Law Enforcement Academy / College of DuPage, and a contributing author to Sanford Weiss' forthcoming book, Forensic Photography for the Preservation of Evidence from CRC Press.


Gray, C. 2019. Roofer pleads guilty in Wisconsin rooftop homicide case. Roofing Contractor. Retrieved online: https://www.roofingcontractor.com/articles/94092-roofer-pleads-guilty-in-wisconsin-roofer-homicide-case

Larsen, J. L. 2011. The importance of evidence collection guidelines in developing a prosecutable case. The Prosecutor. 45(3):29–36.

Masters, N. E. 2002. Safety for the Forensic Identification Specialist (2nd Ed.). Jacksonville, FL: Lightning Powder Co., Inc.

Moreau, D. M. ca. 1980. Crime Scene Search as a Process (training handout). FBI Academy, United States Department of Justice.

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