| Return to the USDOJ/OIG Home Page
Return to the Table of Contents |
The FBI DNA Laboratory: A Review of Protocol and Practice Vulnerabilities
May 2004
Office of the Inspector General
The FBI enforces over 200 federal laws and has jurisdiction to investigate all federal criminal violations not specifically assigned by Congress to another federal agency. Its investigations routinely address matters such as counterterrorism, foreign counterintelligence, organized crime, civil rights, and financial crime. As part of its law enforcement mission, the FBI also is authorized to provide other law enforcement agencies with cooperative services, such as fingerprint identification, laboratory examinations, and police training. Because the successful investigation and prosecution of crimes requires, in many cases, the collection, preservation, and forensic analysis of evidence, the FBI Laboratory Division and the forensic science specialties available to it are a central component of FBI operations.
I. THE FBI LABORATORY DIVISION
The FBI Laboratory provides leadership in the scientific analysis and prosecution of crimes throughout the United States. It is the only full-service federal forensic laboratory and is one of the largest forensic laboratories in the world. According to the FBI, Laboratory activities further three primary goals: 1) to provide forensic services to the FBI and other law enforcement agencies; 2) to deploy effective communications, collection, and surveillance capabilities to support investigative and intelligence priorities; and 3) to provide technical and forensic assistance through research, training, technology transfer, and access to information and forensic databases. The Laboratory seeks to meet these goals through forensic examinations, investigative operations support, research and development, application of information technology, and training.
Laboratory personnel conduct scientific examinations of evidence, free of charge, for federal, state, and local law enforcement organizations within the United States. As part of these examinations, Laboratory personnel may analyze physical evidence ranging from blood and other biological materials to explosives, drugs, and firearms. According to the FBI, the Laboratory conducts more than one million examinations each year.
In March 2003, the Laboratory moved to its new facility in Quantico, Virginia, resulting in the relocation of approximately 650 Laboratory employees. The design of the new facility is meant to provide for ideal security and evidence control. Offices and public areas are separated from the laboratory areas to avoid evidence contamination. Also, laboratory areas are accessed through "biovestibules" that are meant to provide storage and serve as airlocks between laboratories and offices.30
The Laboratory is located organizationally within the Law Enforcement Services Directorate of the FBI. It is comprised of various branches, divided into sections, which are further broken down into units. The subject of this review, the DNAUI, is part of the Scientific Analysis Section, as shown in the following Laboratory organizational structure:
| Federal Bureau of Investigation [Image not available electronically] |
In 1988, a DNA Analysis Unit was established in the Laboratory. Prior to that time, body fluid examinations were performed by the Serology Unit. Although the DNA Analysis Unit was split into two units in 1993, they were re-joined in 1994. In 1998, the DNAUI and DNA Analysis Unit II (DNAUII) were formed. DNAUII was created when the Laboratory established a separate group to analyze a different type of DNA than is analyzed by the DNAUI.
The DNAUI analyzes nuclear DNA, or DNA found in the nucleus of a cell, while DNAUII analyzes mitochondrial DNA, or DNA found in the mitochondria of a cell. The mitochondria are about the size of bacteria and are scattered throughout a cell outside its nucleus. Since there are between 500 to 1,000 mitochondria in every cell, as opposed to one nucleus, mitochondrial DNA analysis affords a better chance of a DNA profile than nuclear DNA analysis in cases where a sample is decayed or degraded, such as skeletal remains that have been exposed to the elements for years. Consequently, the DNAUII receives and analyzes evidence samples and human remains that have not, or most likely will not, generate a traditional STR profile, such as teeth or pieces of bone that have no tissue attached. These types of evidence items are common in cases involving unidentified remains and missing persons. DNAUII receives evidence from across the country, since the specialized equipment, training, and facilities that are required for mitochondrial DNA analysis are usually beyond the resources of state and local laboratories. Further, because mitochondrial DNA analysis is more sensitive to trace amounts of DNA than STR analysis, it requires even greater safeguards in facilities and techniques to avoid contamination.
The DNAUI identifies and characterizes body fluids and body fluid stains recovered as evidence in crimes using traditional serological techniques and related biochemical analysis. These stains are analyzed and compared to results from the known body fluid samples submitted by the victim(s) and/or suspected perpetrator(s). This work is completed in the DNAUI in assembly-line fashion by teams of forensic scientists, which include a Serologist, a PCR Biologist, and an Examiner. The following chart represents the organization of the DNAUI:
| DNA Analysis Unit 1 Organizational Chart [Image not available electronically] |
The DNAUI participates in CODIS, which is administered by the CODIS Unit within the Laboratory. CODIS is a national DNA information repository that allows local, state, and federal crime laboratories to store and compare DNA profiles from crime scene evidence, from convicted offenders, and from unidentified remains. The FBI provides participating laboratories with special software that organizes and manages their DNA profiles and related information, including enabling participating laboratories to compare DNA profiles. CODIS is organized as a hierarchy that encompasses national, state, and local indexes. DNA profiles are uploaded into the national index from the state indexes and into the state indexes from the local indexes. The forensic laboratories at each level of the CODIS hierarchy decide which DNA profiles will be uploaded to the next level, and conversely, the state and national levels determine, based upon applicable state and federal legislation, what profiles they will accept from the local and state indexes.
The DNAUI operates at the "state index" level, meaning that it uploads directly to the national database, or NDIS. The DNAUI has been uploading profiles to NDIS since September 1998. As of February 2004, the DNAUI had submitted approximately 1,602 forensic profiles (DNA profiles resulting from forensic or crime scene analysis work) to NDIS. According to DNAUI management, the Unit uploads approximately 30 forensic profiles per month to the CODIS database. In addition, the DNAUI oversees the Federal Convicted Offender Program, which involves analyzing known DNA samples from convicted felons in the federal system and uploading the resulting profiles to NDIS for comparison to crime scene evidence profiles from across the country. As of February 2004, the DNAUI had uploaded 213 offender profiles to NDIS.31
One of the goals of CODIS is to match DNA profiles from case evidence to other previously unrelated cases or to persons already convicted of other crimes. To determine the extent to which this goal is being met, the CODIS Unit has collected statistics from CODIS participants on the number of investigative leads that have been provided through CODIS' match capabilities. As of February 2004, the DNAUI reported a total of 187 investigations aided by CODIS.32
At the time of our review, the Laboratory's Information and Evidence Management Unit, and specifically the Evidence Control Center (ECC) within that Unit, received all incoming evidence for the Laboratory.33 The ECC staff were responsible for ensuring that the evidence was sealed properly and that its receipt by the FBI was formally documented on a chain-of-custody form. The ECC staff would open the outer layer of packaging to retrieve the submission paperwork and the individually packaged sealed evidence containers. The ECC staff then would review the submission letter to determine the contents of the sealed container and what tests were requested. In addition, ECC staff labeled each evidence container with unique identifying numbers, as well as a Laboratory case number that would link it with other items received on the same case. Those identifiers, along with the information about the submitter and contents, were entered into the ECC's tracking system.
After all intake work was completed, the evidence was placed in secured storage where it would not deteriorate. The ECC then assigned the evidence to a specific unit within the Laboratory, termed the "primary unit." The primary unit was selected based upon an evaluation of the submission paperwork, from which ECC staff determined which unit would need to complete its work first to avoid contamination or deterioration of the evidence and/or would be conducting the most testing. Due to the nature of DNA evidence and its sensitivity to contamination, the DNAUI often served as the primary unit.
After the primary unit assignment was documented in the ECC system, the evidence was transferred to the designated unit and the necessary chain-of-custody documentation was completed. Within the primary unit, a coordinating Examiner was assigned to ensure that the evidence was routed in the proper order to all other units that will be performing tests on the various items of evidence.34
Throughout the analysis process, FBI policy requires that the chain-of-custody documentation be maintained to reflect all inter-unit transfers and to record which personnel processed the evidence. As part of this policy, after all laboratory analysis is completed, an inventory is performed to ensure that the evidence is accounted for. The evidence and all by-products of the analysis process are then repackaged and transferred back to the ECC for return to the submitter.
In those instances where the primary unit is the DNAUI, the coordinating Examiner works with a Serologist and PCR Biologist as a team to inventory evidence items, perform preliminary testing to identify and isolate sources of DNA on those items, and analyze any resulting DNA.
Teams in the DNAUI are divided into a form of assembly line, and each member of the team completes a portion of the analysis process and shares in the responsibility for that process. The three team members and their duties and responsibilities are as follows:
1) The Serologist assists with the initial and final evidence inventories and performs serology testing to determine what body fluids may be present in the evidence. Once body fluid screening is completed for a stain on an item of evidence, a portion of that stain is transferred to the PCR Biologist.
2) The PCR Biologist (the position held by Blake) is responsible for taking cuttings, swabs, or other material containing DNA from the Serologist and completing the PCR/STR process through the production of GeneScan® and Genotyper® data for the Examiner. Included in this process are the following activities:
3) The Examiner on each team serves as the first-line supervisor for the team members and are responsible for the work performed by them. Further, unless otherwise specified in written protocols and procedures, the Examiners are given sufficient autonomy to direct how the team will function. Examiners typically can assign work, structure communications, define the decision-making authority of other team members, and specify the level of direct involvement of the Examiner in the work of the other team members.
The Examiner on the team is supplied with all of the documentation from the Serologist and PCR Biologist, as well as the data produced from the capillary electrophoresis process (complete with sample lists, injection lists, and Genotyper® data). The Examiner is responsible for ensuring that:
In addition, the Examiner is responsible for reviewing the filtered capillary electrophoresis data, or Genotyper® data, and drawing conclusions about the usability of that data based upon the control results. For this review, the sample and injection lists serve as a guide to show the order that the samples were analyzed and to indicate the presence of the appropriate control samples. Each Examiner decides whether to complete this data review from printouts or directly from the electronic data on the computer. If there are data quality problems, or control result problems, then the Examiner will work with the PCR Biologist to troubleshoot those issues. Otherwise, the Examiner proceeds to draw conclusions about the evidence based upon the data generated from the capillary electrophoresis. The Examiner then writes a report stating those conclusions and, if necessary, later testifies in court about them.
After the discovery of Blake's misconduct, the DNAUI changed its policies to require that the GeneScan® data be supplied to and reviewed by the Examiner, as well as the Genotyper® data, since it was the failure of Examiners to review GeneScan® data that allowed Blake to proceed undetected. See generally Chapter Four, Section II (describing the DNAUI GeneScan® review policy) and Chapter Four, Section V.C (describing the Laboratory's initial remedial actions after the discovery of Blake's misconduct).
DNAUI team members demonstrate compliance with the Laboratory's protocols primarily through the documentation that they produce as they perform their work. Although the Examiner can be involved at critical junctures in the DNA analysis process, the Examiner does not witness most of the work performed. Consequently, team members must thoroughly document their work in the case file to establish for the Examiner that they have followed the applicable protocols.
According to DNAUI personnel and the written procedures for case file documentation, a case file should include the following:
Both technical and administrative case file reviews are required for every DNAUI case. The initial technical review is performed by the team's Examiner. In addition, another Examiner who is not involved in the case performs an independent technical review or peer review of the case file. The peer reviewer draws his or her own conclusions from the supporting documentation without regard to the conclusions or report produced by the first Examiner. The results of these evaluations are then compared for consistency and any discrepancies resolved. Finally, the Unit Chief conducts an administrative review of the case file and examines the order and completion of the case file documents, report format, and other administrative items.
According to DNAUI personnel, a thorough technical or peer review generally involves checking:
After the Examiner reviews these items, the Examiner (whether the initial Examiner or peer reviewer) determines what conclusions and statistics should be reflected in the report. For the peer reviewer, this determination is compared with the actual case report to verify that both Examiners agree. Finally, if the profile will be uploaded to CODIS, both reviewers confirm that the identifying paperwork listing the DNA profile is correct, and that the profile is appropriate for inclusion in the database.
The activities of the DNAUI are governed not only by the Quality Assurance Standards that apply to all forensic DNA laboratories (as described in Chapter Two, Section II), but also by the FBI Laboratory's own procedures and protocols. These guidelines are contained in five FBI documents: 1) the FBI Laboratory Division Quality Assurance Manual; 2) the DNA Analysis Unit I Quality Assurance Manual; 3) the FBI Laboratory Division Caseworking Procedures Manual; 4) the Procedures for the Serological Identification of Biological Substances on Evidentiary Materials; and 5) the Short Tandem Repeat Analysis Protocol. As explained in Chapter Five, Section I (Assessment Foundation and Process), the OIG's assessment of vulnerabilities in the DNAUI's internal control structure focused on these protocols.36 A brief description of each document is provided below:
The FBI Laboratory Quality Assurance Manual addresses laboratory policies and operational practices. It is organized into 17 sections and identifies requirements and guidance for case documentation, evidence control, court testimony and testimony monitoring, authorization of deviations, corrective action, document control, calibration and maintenance, internal audits, laboratory security, proficiency testing, and conflict resolution. The document applies to all units in the Laboratory and therefore does not contain guidance specific to the DNAUI.
The DNAUI Quality Assurance Manual is organized into 20 sections and covers topics including:
The Caseworking Procedures Manual provides guidance for all units within the Laboratory. It is divided into 12 sections, each covering a different aspect of the caseworking process. Topics include:
This document is written specifically for DNAUI Serologists and identifies the methods and requirements for each of the serology procedures utilized by the DNAUI. It contains 72 sections, describes 6 routine and 8 non-routine serological procedures, and provides a general discussion of guidelines regulating laboratory set-up.
The STR Protocol specifies the procedures and requirements for processing DNA evidence using short tandem repeat (STR) analysis. See generally Chapter Two, Section I.C (describing STR analysis). The document is divided into 46 sections and covers the major processes involved in STR analysis, including extraction, quantification, amplification, electrophoresis, data evaluation and interpretation, and report writing. In addition, the Protocol provides information that applies generally to STR analysis, including guidelines for reagents, supplies, and equipment; special quality control considerations; and laboratory set-up instructions.
The protocols above implement the Quality Assurance Standards that apply to all forensic DNA laboratories. The national standards require laboratories to develop and adhere to operational standards that are tailored to their specific functions and circumstances. In general, these standards afford laboratories broad discretion regarding the content of their written procedures. See Section 9 "Analytical Procedures" in Appendix 3.
Certain DNA protocols are specifically designed to protect the integrity of the STR process by helping to identify the presence of contamination and prevent its occurrence. They include: 1) the required use of quality controls; 2) on-going cleaning and decontamination; and 3) the systematic separation of sample sources and of stages in the analysis process.37
As discussed in Chapter Two, Section I (General Principles of DNA Analysis) of this report, the use of positive and negative controls and reagent blanks serves as an indicator of contamination and whether the equipment and reagents functioned properly during the analysis process. The positive control allows the PCR Biologist and Examiner to determine the accuracy and consistency of the amplification and capillary electrophoresis processes each time DNA samples are analyzed. The negative control and the reagent blank reveal whether contamination was present in the reagents or whether contamination was introduced during the testing process. DNAUI procedures require the PCR Biologist to process positive and negative controls and reagent blanks with every batch of DNA samples analyzed. The Examiners, along with the PCR Biologists, analyze the control results to ensure that the data generated from the DNA samples meet the quality standards established for the resulting DNA profiles.
The failure to analyze properly the positive and negative controls and reagent blanks does not necessarily render DNA testing results inaccurate. Rather, it limits the conclusions that the DNAUI scientists may draw from the testing. Without properly analyzing the negative control and the reagent blank, DNAUI scientists cannot be sure that the only source of the test results is the DNA from the evidence under examination. The results could reflect impurities in the reagents or contamination introduced during the testing process. If the positive control is not analyzed properly, the DNAUI scientists cannot evaluate how well the amplification and capillary electrophoresis processes worked.
Adequate cleaning and decontamination procedures limit the possibility that forensic scientists will contaminate DNA samples during the testing process. Two types of contamination are of concern: 1) an evidence item or a DNA sample can be contaminated with DNA from a different case or from a different piece of evidence from the same case; and 2) the forensic scientist might also contaminate evidence with his or her own DNA.
The DNAUI cleaning and decontamination procedures can be summarized as follows:
In addition, the DNAUI uses a contamination log to track occurrences of contamination. The log assists Unit management in identifying when staff members may need additional training or oversight, or in determining whether a procedure needs to be strengthened to avoid future incidents of contamination.
The separation of the different types of samples and stages in the analysis process is important in reducing the possibility that DNA from one sample can contaminate another sample. For instance, samples from crime scene evidence (unknown samples) should be processed separately from samples submitted by suspects or other known individuals (known samples) to eliminate the risk of the suspect's DNA contaminating an unknown DNA sample. In the same way, it is also important to separate large and small samples of DNA to avoid the risk that the low quantity DNA will be contaminated by the high quantity DNA sample. Depending on the level of contamination, the DNA from the low quantity sample could be "drowned out" by the contamination, thus altering the test results for the low quantity sample.
The DNAUI Serologists and PCR Biologists attempt to limit such cross-contamination through the following procedures:
Several steps in the DNA testing process are performed in separate rooms in the DNAUI's new facility at Quantico, Virginia. The Serologists examine evidence and take cuttings or swabbings in one room. The PCR Biologists extract the DNA from the cuttings or swabbings in a second room under a hood. They also prepare the extracted DNA for amplification in that room. The actual amplification process takes place in a third room.
Once the DNA has been amplified, the DNAUI addresses the potential for amplification-related contamination as follows:
The foregoing descriptions of the DNA analysis process, the standards and protocols that govern that process, and the structure and operations of the FBI Laboratory, particularly the DNAUI, provide context necessary to understand fully the findings and recommendations of our vulnerability assessment, as well as Blake's wrongdoing and how she exploited a loophole in the Laboratory's protocols to avoid detection. Before proceeding to address the results of our assessment, we describe below the events that precipitated the review, namely the discovery of Blake's disregard of protocols in the DNAUI.