- 9/11 Commission Reports
- Central Intelligence Agency (CIA) Records
- Federal Bureau of Investigation (FBI) Records
- Other 9/11 Related Documents
- Federal Building and Fire Investigation of the World Trade Center Disaster by the National Institute of Standards and Technology
- Thesis Papers Regarding 9/11
The National Commission on Terrorist Attacks Upon the United States, also known as the 9/11 Commission, was set up on November 27, 2002 "to prepare a full and complete account of the circumstances surrounding the September 11, 2001 attacks", including preparedness for and the immediate response to the attacks.
- The 9/11 Commission Report - Executive Summary
- The 9/11 Commission Report
- Aviation Security-Related Findings and Recommendations of the 9/11 Commission [21 Pages, 162 KB] - The 9/11 Commission found that al Qaeda operatives exploited known weaknesses in U.S. aviation security to carry out the terrorist attacks of September 11, 2001. While legislation and administration actions after September 11, 2001 were implemented to strengthen aviation security, the 9/11 Commission concluded that several weaknesses continue to exist. These include perceived vulnerabilities in cargo and general aviation security as well as inadequate screening and access controls at airports. The 9/11 Commission issued several recommendations designed to strengthen aviation security by: enhancing passenger pre-screening; improving measures to detect explosives on passengers; addressing human factors issues at screening checkpoints; expediting deployment of in-line baggage screening systems; intensifying efforts to identify, track, and screen potentially dangerous cargo; and deploying hardened cargo containers on passenger aircraft. In addition to these specific recommendations, an overarching recommendation for transportation security policy asserts that priorities should be set based on risk, and the most practical and cost effective deterrents should be implemented assigning appropriate roles and missions to federal, state, and local authorities, as well as private stakeholders.
- Implementing Recommendations of the 9/11 Commission Act: Coast Guard Impact [31 Pages, 352 KB] - The Implementing Recommendations of the 9/11 Commission Act of 2007 (9/11 Act) sought to codify the recommendations of the 9/11 Commission Report. This essay summarizes the 9/11 Act's impact on the Coast Guard. Given the cascade of security legislation and other policy guidance subsequent to 9/11 and prior to this law, many of the recommendations of the 9/11 Report have already been initiated. While the 9/11 Act does not require immediate wholesale change of the Coast Guard, in the near-term the Coast Guard should work especially closely with DHS in regards to container security, northern border security, incident command credentialing, and radio interoperability. In a broader context, the 9/11 Act again raises expectations for interagency expertise which calls for more than the current ad hoc professional development initiatives, further justifying proposals for a capstone homeland security institution such as the National Homeland Security University. The greatest long-term impact to the Coast Guard may be the new Quadrennial Homeland Security Review since it carries the potential to become the source of major reorganization, reprioritization, and policy change. Accordingly, it will be critical for the Coast Guard to provide a cohesive document to inform proper budgetary, mission, and force structure decisions.
- U.S. Anti-Terror Strategy and the 9/11 Commission Report [15 Pages, 352 KB] - On July 22, 2004 the 9/11 Commission released its final report. The report calls for changes to be made by the executive branch and Congress to more effectively protect the nation in an age of modern terrorism. The report provides 41 concrete recommendations. Generally, the recommendations of the 9/11 Commission as they relate to strategy content and implementation appear consistent with, and supportive of, the National Strategy. Few question the 9/11 Commission Report's overarching premise that U.S. counterterrorism structure, strategy, and implementation can be improved. Some, however, see certain Commission recommendations as incomplete, if not flawed. They suggest that the Commission is often focused on the "last war" and not a future one and that it consciously avoids tackling some of the more complex, yet pressing issues. For example, as its first recommendation, the Commission stresses the need for identifying and prioritizing terrorist sanctuaries, with a focus on failed states. Some assert, however, that terrorists are increasingly returning to their politically stable home countries for sanctuary where they blend into local communities, where their training camps are in civilian housing complexes, and where their bomb factories are in private residences. Although a number of the Commission's recommendations fall within the category of preventing the growth of Islamic extremism, none addresses directly the issue of confronting incitement to terrorism when promoted, countenanced, or facilitated by the action or inaction of nation states. With terrorists able to change targets, tactics, and weapons on short notice, many argue that a successful counterterrorism strategy and institutional structures will need similar flexibility. The degree to which such flexibility will be built into strategy, and into any new institutional structures recommended by the 9/11 Commission, is yet to be determined.
- OIG Report on CIA Accountability with Respect to the 9/11 Attacks - Executive Summary [19 Pages, 1mb]
- 9/11 FBI Report, 2 February 2003 [10 Pages, 9.07mb]
- A Review of the FBI's Handling of Intelligence Information Related to the September 11 Attacks, (November 2004), Released Publicly June 2006 [449 Pages, 9.07mb]
- A Review of the FBI's Handling of Intelligence Information Prior to the September 11 Attacks, (released publicly June 2005) (Redacted and Unclassified), November 2004 [328 Pages, 32.43mb]
- The September 11 Detainees: A Review of the Treatment of Aliens Held on Immigration Charges in Connection with the Investigation of the September 11 Attacks, June 2003 [239 Pages, 12.5mb]
- The Immigration and Naturalization Service's Contacts With Two September 11 Terrorists: A Review of the INS's Admissions of Mohamed Atta and Marwan Alshehhi, its Processing of their Change of Status Applications, and its Efforts to Track Foreign Students in the United States, May 2002 [212 Pages, 1.6mb]
- 1998 Terrorist Warning on Men Training at Oklahoma Airports [1 Pages]
- 9/11 Ten Years After: Command, Control, Communications Remain an Issue [36 Pages, 421 KB] - This research paper reviews current emergency management capability to respond to significant incidents, both natural and manmade. In such incidents, multiple agencies must respond, manage forces, and provide critical support as a cohesive team. These organizations span the gamut of local, tribal, state, and federal levels of government and the private sector. They include the broad range of first responders, fire, medical, and police. The unity of effort needed to provide timely, efficient, and integrated responses can only be achieved through effective command, control, and communications (C3) within and among responding forces. A unified response requires interoperable communications among all agencies, at all levels; a mechanism to track all responding forces; and a common operating picture that fuses and displays disparate data. This paper reviews current national policies, procedures, and technologies for managing large-scale emergencies. It identifies challenges and opportunities for improvement. It concludes with recommendations for implementing a nationwide interoperable communications system that, along with an effective tracking system, will facilitate the formulation of a COP for first responders.
- Annotated Bibliography of Government Documents Related to the Threat of Terrorism and the Attacks of September 11, 2001 [99 Pages]
- Assessing the Effectiveness of Post-9/11 Intelligence Information Sharing [31 Pages, 377 KB] - In the wake of the terrorist attacks of 11 September 2001, the 9/11 Commission determined that intelligence related to the attack was not shared across the Intelligence Community (IC), and especially between the Central Intelligence Agency (CIA) and the Federal Bureau of Investigations (FBI). Specifically the Commission faulted the IC for being parochial, secretive, and delinquent in sharing important intelligence. Despite the 9/11 Commission's recommendations, including the creation of the Office of the Director of National Intelligence (ODNI), and institutions such as the National Counterterrorism Center (NCTC), the parochialism continues and information sharing across the IC remains a critical problem. As the 2009 Christmas Day failed bombing of the Northwest Flight reminded us, the lack of IC sharing can have tragic consequences and that it still remains a work in progress.
- The Authority and Suitability of Military Commissions to Try the September 11th Terrorists [43 Pages]
- Bin Laden Preparing to Hijack US Aircraft and Other Attacks 12/4/1998 [2 Pages]
- Flashman's Revenge: Central Asia After September 11 [9 Pages]
- Video of Flight 77 and Photographs of Flight 93 - Information is classified as of October 2005. [2 Pages]
- Wasted Lessons of 9/11: How the Bush Administration Has Ignored the Law and Squandered its Opportunities to Make Our Country Safer [54 Pages, 1.03 MB] - When President George W. Bush signed H.R. 1, "Implementing the 9/11 Commission Recommendations Act of 2007," into law on August 3, 2007 without any limiting statement, it seemed that the unfulfilled security recommendations of the 9/11 Commission would finally be implemented. To ensure that they were, over the past year the Majority staffs of the Committees on Homeland Security and Foreign Affairs have conducted extensive oversight to answer the question: How is the Bush Administration doing on fulfilling the requirements of H.R. 1 (P.L. 110-53)? The Majority staffs of the two Committees prepared this report to summarize their findings.
NIST NCSTAR 1: Federal Building and Fire Safety Investigation of the World Trade Center Disaster
This is the final report on the National Institute of Standards and Technology (NIST) investigation of the collapse of the World Trade Center (WTC) towers, conducted under the National Construction Safety Team Act. This report describes how the aircraft impacts and subsequent fires led to the collapse of the towers after terrorists flew jet fuel laden commercial airliners into the buildings; whether the fatalities were low or high, including an evaluation of the building evacuation and emergency response procedures; what procedures and practices were used in the design, construction, operation, and maintenance of the towers; and areas in current building and fire codes, standards, and practices that warrant revision.
Extensive details are found in the 42 companion reports. (The final report on the collapse of WTC 7 will appear in a separate report.) Also in this report is a description of how NIST reached its conclusions. NIST complemented in-house expertise with private sector technical experts; accumulated copious documents, photographs, and videos of the disaster; established baseline performance of the WTC towers; performed computer simulations of the behavior of each tower on September 11, 2001; combined the knowledge gained into a probable collapse sequence for each tower; conducted nearly 1,200 first-person interviews of building occupants and emergency responders; and analyzed the evacuation and emergency response operations in the two high-rise buildings.
The report concludes with a list of 30 recommendations for action in the areas of increased structural integrity, enhanced fire endurance of structures, new methods for fire resistant design of structures, enhanced active fire protection, improved building evacuation, improved emergency response, improved procedures and practices, and education and training.
- Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Tower
NIST NCSTAR 1-1: Design, Construction, and Maintenance of Structural and Life Safety Systems
The collapse of World Trade Center (WTC) 1, 2, and 7 resulted from structural damage from direct and indirect effects of aircraft impact and the ensuing fires. Thus, for collapse analyses of these buildings, knowledge of the physical state of the structural and fire safety systems prior to the aircraft impact is essential. To obtain information for the collapse analysis of the buildings, National Institute of Standards and Technology reviewed design and construction documents, correspondence, and memoranda related to the building projects; interviewed individuals involved in the design, construction, and maintenance of the buildings; obtained information from regulatory and emergency services agencies of New York City; and reviewed books and published journal and magazine articles related to the WTC building projects.
Information obtained from various sources are synthesized and summarized in this report. Specifically, this report presents (1) provisions used to design and construct the structural, fire protection and egress systems of the buildings; (2) tests performed to support the design of these systems; (3) criteria that governed the design of the structural and fire protection systems; (4) methods used to proportion structural members and other components of the buildings; (5) innovative features, technologies and materials that are incorporated in design and construction of the structural and fire protection systems; (6) details of deviations to the contract documents granted by Port Authority of New York and New Jersey; (7) fabrication and inspection requirements at the fabrication yard; and (8) inspection protocols during construction.
- NIST NCSTAR 1-1: Design, Construction, and Maintenance of Structural and Life Safety Systems
- NIST NCSTAR 1-1A: Design and Construction of Structural Systems
- NIST NCSTAR 1-1B: Comparison of Building Code Structural Requirements
- NIST NCSTAR 1-1C: Maintenance and Modifications to Structural Systems
- NIST NCSTAR 1-1D: Fire Protection and Life Safety Provisions Applied to the Design and Construction of World Trade Center 1, 2, and 7 and Post-Construction Provisions Applied after Occupancy
- NIST NCSTAR 1-1E: Comparison of Codes, Standards, and Practices in Use at the Time of the Design and Construction of World Trade Center 1, 2, and 7
- NIST NCSTAR 1-1F: Comparison of the 1968 and Current (2003) New York City Building Code Provisions
- NIST NCSTAR 1-1G: Amendments to the Fire Protection and Life Safety Provisions of the New York City Building Code by Local Laws Adopted while World Trade Center 1, 2, and 7 Were in Use
- NIST NCSTAR 1-1H: Post-Construction Modification to Fire Protection and Life Safety Systems of the World Trade Center Towers
- NIST NCSTAR 1-1I: Post-Construction Modifications to Fire Protection, Life Safety, and Structural Systems of World Trade Center 7
- NIST NCSTAR 1-1J: Design, Installation, and Operation of Fuel Systems for Emergency Power in World Trade Center 7
NIST NCSTAR 1-2: Baseline Structural Performance and Aircraft Impact Damage Analysis of the World Trade Center Towers
The baseline structural performance and aircraft impact damage analysis of the National Institute of Standards and Technology (NIST) Investigation of the World Trade Center (WTC) disaster had two primary tasks: (1) to develop reference structural models of the WTC towers and use these models to establish the baseline performance of each of the towers under gravity and wind loads, and (2) to estimate the damage to the towers due to aircraft impacts and establish the initial conditions for the fire dynamics modeling and the thermal-structural response and collapse initiation analysis. This report provides the technical approach, methodology, and results related to both tasks.
The focus of the analysis was to analyze the aircraft impacts into each of the WTC towers to provide the following: (1) estimates of probable damage to structural systems, including exterior walls, floor systems, and interior core columns; (2) estimates of the aircraft fuel dispersion during the impact; and (3) estimates of debris damage to the building nonstructural contents, including partitions and workstations. The results were to be used to estimate the damage to fireproofing based on the predicted path of the debris field inside the towers. This analysis thus estimated the condition of the two WTC towers immediately following the aircraft impacts and established the initial conditions for the fire dynamics modeling and the thermal-structural response and collapse initiation analysis. The impact analyses were conducted at various levels of complexity including: (1) the component level, (2) the subassembly level, and (3) the global level to estimate the probable damage to the towers due to aircraft impact.
- NIST NCSTAR 1-2: Baseline Structural Performance and Aircraft Impact Damage Analysis of the World Trade Center Towers
- NIST NCSTAR 1-2A: Reference Structural Models and Baseline Performance Analysis of the World Trade Center Towers
- NIST NCSTAR 1-2B: Analysis of Aircraft Impacts into the World Trade Center Towers (Chapters 1-8)
- NIST NCSTAR 1-2B: Analysis of Aircraft Impacts into the World Trade Center Towers (Chapters 9-11)
NIST NCSTAR 1-3: Mechanical and Metallurgical Analysis of Structural Steel
This report is an overview of the results of the mechanical and metallurgical analysis of structural steel from the World Trade Center (WTC), part of the National Institute of Standards and Technology Investigation of the WTC disaster of September 11, 2001. The goal of the study was threefold: Determine mechanical properties of WTC structural steel, Determine the quality of the steel and if design requirements were met, and Analyze the recovered steel to provide insight into failure mechanisms to guide and/or validate models of building performance. Structural steel recovered from the WTC site was analyzed for composition, microstructure, and mechanical properties, including room temperature properties (for modeling baseline building performance), high temperature properties (for modeling structural response of the building to fire), and behavior at high strain rates (for modeling airplane impact). Failure analysis of the recovered steel, complemented by pre-collapse photographs of the damaged building, was used to establish failure modes and temperature excursions experienced by the steel. In addition, documents from the construction era covering issues ranging from steel specifications to engineering design drawings were used to help interpret the results and supplement models of mechanical properties used in the models of building performance.
- NIST NCSTAR 1-3: Mechanical and Metallurgical Analysis of Structural Steel
- NIST NCSTAR 1-3A: Contemporaneous Structural Steel Specifications
- NIST NCSTAR 1-3B: Steel Inventory and Identification
- NIST NCSTAR 1-3C: Damage and Failure Modes of Structural Steel Components
NIST NCSTAR 1-4: Active Fire Protection Systems
The National Institute of Standards and Technology investigation of active fire protection systems in World Trade Center (WTC) 1, 2, and 7 included the design, installation, capabilities, and performance on September 11, 2001, of the automatic fire sprinkler, standpipe, standpipe preconnected hoses, fire alarm, and smoke management systems. The purpose and normally expected performance of each active fire protection system in the buildings are described, as well as details about the systems installed in WTC 1, 2, and 7. Using fire protection engineering methods, the capabilities of the installed systems to respond to various fire threats from normal office fires up to and including the extraordinary challenge of the fires ignited by the aircraft impacts on September 11, 2001, were assessed. Information from The Fire Department of the City of New York records was used to document the history of significant fire events in WTC 1, 2, and 7. Findings of the investigation are presented with regard to the fire suppression, fire alarm, and smoke management systems installed on the day the buildings collapsed.
- NIST NCSTAR 1-4: Active Fire Protection Systems
- NIST NCSTAR 1-4A: Post-Construction Fires prior to September 11, 2001
- NIST NCSTAR 1-4B: Fire Suppression Systems
- NIST NCSTAR 1-4C: Fire Alarm Systems
- NIST NCSTAR 1-4D: Smoke Management Systems
NIST NCSTAR 1-5: Reconstruction of the Fires in the World Trade Center Towers
The collapses of the World Trade Center towers on September 11, 2001, resulted from a combination of aircraft impact damage and the ensuing fires.
- NIST NCSTAR 1-5: Reconstruction of the Fires in the World Trade Center Towers
- NIST NCSTAR 1-5A: Visual Evidence, Damage Estimates, and Timeline Analysis (Chapters 1-8)
- NIST NCSTAR 1-5A: Visual Evidence, Damage Estimates, and Timeline Analysis (Chapters 9-Appendix C)
- NIST NCSTAR 1-5B: Experiments and Modeling of Structural Steel Elements Exposed to Fire
- NIST NCSTAR 1-5C: Fire Tests of Single Office Workstations
- NIST NCSTAR 1-5D: Reaction of Ceiling Tile Systems to Shocks
- NIST NCSTAR 1-5E: Experiments and Modeling of Multiple Workstations Burning in a Compartment
- NIST NCSTAR 1-5F: Computer Simulation of the Fires in the World Trade Center Towers
- NIST NCSTAR 1-5G: Fire Structure Interface and Thermal Response of the World Trade Center Towers
NIST NCSTAR 1-6: Structural Fire Response and Probable Collapse Sequence of the World Trade Center Towers
One of the four main objectives of the National Institute of Standards and Technology (NIST) investigation of the collapse of the World Trade Center (WTC) towers was to determine why and how the two towers collapsed. Events that played a significant role in the structural performance of the towers were the aircraft impact, the rapid ignition of fires on multiple floors, the growth and spread of fires and the structural weakening resulting from effects of high temperatures. The passive fire protection applied to the steel structural components in the WTC towers was investigated to provide information on the in place condition of the fire protection before and after aircraft impact. Standard fire resistance tests were conducted to establish the appropriate classification (fire resistance rating) of the original design of the WTC floor system and to develop insight into the structural performance of the composite steel and concrete floor system under exposure to a standard fire. Results of simulations of the aircraft impacts were used to predict damage to the structure, fire protection, and partition walls in the path of the debris field. Characterization of the temperatures of the structural components, determined from simulated WTC fires, allowed the calculation of the performance of major subsystems constituting the structural system of the towers including the core framing, the exterior wall (columns and spandrels), and full tenant floors. Insights gained from these analyses were used, in turn, to formulate and execute nonlinear, temperature-dependent finite element analyses of global structural systems to predict the collapse sequence of each tower. The structural analyses were guided, and where possible validated, by observations made from the review of thousands of photographs and video recordings. This report covers the characterization of the conditions of the WTC towers before the attacks, their weakening due to the aircraft impacts, the response of the structural systems to the subsequent growth and spread of fires, and the progression of local failures that led ultimately to the total collapse of both towers.
- NIST NCSTAR 1-6: Structural Fire Response and Probable Collapse Sequence of the World Trade Center Towers
- NIST NCSTAR 1-6A: Passive Fire Protection
- NIST NCSTAR 1-6B: Fire Resistance Tests of the Floor Truss Systems
- NIST NCSTAR 1-6C: Component, Connection, and Subsystem Structural Analysis
- NIST NCSTAR 1-6D: Global Structural Analysis of the Response of the World Trade Center Towers to Impact Damage and Fire
NIST NCSTAR 1-7: Occupant Behavior, Egress, and Emergency Communication
This report describes the occupant evacuation of World Trade Center (WTC) 1 and WTC 2 on September 11, 2001. Multiple sources of information were collected and analyzed: over 1,000 new interviews with survivors (including 803 telephone interviews, 225 face-to-face interviews, and 5 focus groups); over 700 published interviews; 9-1-1 emergency calls; transcripts of emergency communications, historical building design drawings, memoranda, and calculations; formal complaints filed with the Occupational Safety and Health Administration; and other relevant materials. The egress system, including stairwells and elevators, was described and compared to requirement of both contemporary and current code requirements. This report documents the emergency procedures, both as they were designed to be implemented, as well as how they were actually implemented on September 11, 2001.
- NIST NCSTAR 1-7: Occupant Behavior, Egress, and Emergency Communication
NIST NCSTAR 1-8: The Emergency Response Operations
The September 11, 2001, attack on the World Trade Center (WTC) caused the deaths of 2,749 people. Included in the group were approximately 421 emergency responders from The Fire Department of the City of New York (FDNY), The New York City Police Department (NYPD), the Port Authority Police Department (PAPD), The Port Authority of New York and New Jersey (PANYNJ), from WTC security firms, and volunteer emergency responders who were in the WTC area of the city when the attack occurred. This report addresses the operations of these emergency responders, the technologies used during WTC operations, and the guidelines and practices that governed these operations. The objectives of this study were to 1) fully document what happened during the response by the emergency services to the attacks on the WTC, up to the time of collapse of WTC 7; (2) identify issues that need to be addressed in changes to practice, standards, and codes; (3) identify alternative practices and/or technologies that may address these issues; and (4) identify R&D needs that advance the safety of the fire service in responding to massive fires in tall buildings.
NIST NCSTAR 1A: Final Report on the Collapse of World Trade Center Building 7
This is the final report on the National Institute of Standards and Technology (NIST) investigation of the collapse of World Trade Center Building 7 (WTC 7), conducted under the National Construction Safety Team Act. This report describes how the fires that followed the impact of debris from the collapse of WTC 1 (the north tower) led to the collapse of WTC 7; an evaluation of the building evacuation and emergency response procedures; what procedures and practices were used in the design, construction, operation, and maintenance of the building; and areas in current building and fire codes, standards, and practices that warrant revision. Extensive details are found in the companion reports, NIST NCSTAR 1-9 and NIST NCSTAR 1-9A.
- Final Report on the Collapse of World Trade Center Building 7 *
NIST NCSTAR 1-9: Structural Fire Response and Probable Collapse Sequence of World Trade Center Building 7 (two volumes)
This is the primary technical report on the investigation of the collapse of World Trade Center Building 7 (WTC 7), providing technical details of all aspects of the investigation. This report also contains five appendices, which provide supporting background information on the Con Edison substation in WTC 7, analysis of the September 11, 2001 seismogram data recorded near the WTC site, video analysis of WTC 7 building vibrations before its collapse, analyses of hypothetical blast scenarios, and plasticity and creep models for WTC 7 steels.
- NIST NCSTAR 1-9: Volume 1: Chapters 1 - 8 *
- NIST NCSTAR 1-9: Volume 2: Chapters 9 - Appendix E *
- NIST NCSTAR 1-9A: Global Structural Analysis of the Response of World Trade Center Building 7 to Fires and Debris Impact Damage *
Post 9/11 World Re: Terrorism
- Dragon on Terrorism: Assessing China's Tactical Gains and Strategic Losses Post-September 11 [70 Pages]
- The Impact of the September 11, 2001 Terrorist Attacks on U.S. - China Relations [75 Pages]
- The National Missile Defense Debate in the Post 9-11 Context [40 Pages]
- Strange Bedfellows: The American Public and Its Military in the Aftermath of September 11th [50 Pages]
- CBRN Terrorism Obsession Prior to 9/11 [103 Pages, 620kb]- 9/11 highlighted failures by both the intelligence and policymaking communities, and these failures were identified by the 9/11 Commission. These failures only related to the inability of the intelligence community to imagine how terrorists might use aircraft as a suicide vehicle, and how politicians failed to eliminate the al-Qaeda threat and Osama bin Laden. Completely unnoticed by the 9/11 Commission, but acknowledged by many within the academic community, was a failure of academia to understand the threat by al-Qaeda and focus too much on weapons of mass destruction terrorism. This thesis examines the question: To what extent were the academic, policymaking, and intelligence communities obsessed with chemical, biological, radiological, and nuclear (CBRN) terrorism prior to 9/11? The thesis concludes that CBRN terrorism was a concern, but was not the greatest national security threat prior to 9/11.
- The Nation That Cried Lone Wolf: A Data-Driven Analysis of Individual Terrorists in the United States Since 9/11 [111 Pages, 560kb]- Lone-wolf terrorist attacks have occurred in the United States throughout the country's history. Attempted attacks from individual terrorists unaffiliated with terrorist groups may be becoming more prevalent. Both the general public and government officials acknowledge the presence and importance of these attacks; however, relatively little literature exists on the subject compared to group terrorism. Much of the information on lone wolves has been established by case study, inference, and known characteristics of group terrorism. The purpose of this study is to analyze the characteristics of lone-wolf terrorism through formal statistical models. The study synthesizes data with case study research and other literature to formulate a base of knowledge for lone-wolf terrorism. The study demonstrates that no single dispositional profile of a lone-wolf terrorist exists. The individuals who engage in the tactic of lone-wolf terrorism form a unique ideology that combines personal grievances with common terrorist goals. Still, many lone-wolf cases exhibit certain characteristics. This thesis analyzes these characteristics and their relationship to successful attacks. Data on the characteristics, goals, and motivations of lone wolves can form the basis of policies to curb lone-wolf terrorism and its effects. The appendix contains brief descriptions of 53 lone-wolf terrorist cases that occurred in the United States from September 2001 to November 2011. The descriptions include the attacker's name, month and year of the attack, and a brief description of what happened.