Frequently Asked Questions

Terrorism and Targeted Violence (T2V) in the United States is a project housed at the National Consortium for the Study of Terrorism and Responses to Terrorism (START) the University of Maryland that seeks to provide policymakers, practitioners, researchers, journalists, and the general public with data and analysis on violent events occurring in the United States and its territories that are designed to have a significant impact on public safety and/or the security of critical infrastructure and key community services. Consistent with the Department of Homeland Security's Strategic Framework for Countering Terrorism and Targeted Violence Implementation Plan, the objective of T2V is to create robust, comprehensive data that are widely accessible to a variety of audiences and to provide critical insights on key questions about patterns of targeted violence in the United States.

The T2V project is funded by the Department of Homeland Security Science and Technology Social Science Technology Center as Task 1 of "Terrorism and Targeted Violence Research and Evaluation" (award #24STFRG00019). The views and conclusions of the project should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security, the University of Maryland, or START.

No, the T2V data only include events that occurred within the United States and its territories (e.g., Puerto Rico).

To have access to enough reliable information to determine if an event meets the T2V inclusion criteria, as well as to extract the event's relevant details, it is necessary to collect the data on a time lag. We anticipate that T2V data collection will get closer to real-time in the coming months, but we will maintain at least a one-month time lag to ensure data accuracy.

The T2V data are compiled entirely from public sources. The two primary sources of information for the T2V data are news reports and official court records. The T2V data do not use social media posts or other sources of questionable validity. News reports are only used if they are determined to be of high validity (i.e., those that routinely report externally verifiable content, those that are free from outside influence, and those that prioritize primary rather than secondary information) and accurate. In most cases, these reports come from local newspapers and news affiliates (e.g., the St. Louis Post-Dispatch, FOX4News, etc.) or national outlets with longstanding reputations for publishing factual content (e.g., the Wall Street Journal, New York Times, etc.). When possible, the T2V team tries to corroborate each piece of information among multiple independent open sources.
T2V events are identified by a trained staff of full time researchers and are verified by the project's data collection manager and principal investigator. The details of the events in T2V are coded by full time staff and students trained through START's internship program. All event details are reviewed by the project's data collection manager and/or principal investigator.

The T2V projects uses the definition of targeted violence found in the Department of Homeland Security's 2019 Strategic Framework:

"Any incident of violence that implicates homeland security and/or U.S. Department of Homeland Security activities, and in which a known or knowable attacker selects a particular target prior to the violent attack. Unlike terrorism, targeted violence includes attacks otherwise lacking a clearly discernible political, ideological, or religious motivation, but that are of such severity and magnitude as to suggest an intent to inflict a degree of mass injury, destruction, or death commensurate with known terrorist tactics. In the Homeland, targeted violence has a significant impact on the safety and security of our communities, schools, places of worship, and other public gatherings."

The T2V database includes successful, failed, and foiled events that meet the following inclusion criteria:

A premeditated act that is dangerous to, or potentially dangerous to, human life or the security of critical infrastructure or key resources;
Is a violation of the criminal laws of the United States or of any subdivision of the United States;
Is intended to intimidate, coerce, or otherwise impact a broader population beyond the target(s) of the immediate act or to generate publicity for the perpetrator and/or their grievances;
And occurs within the territorial jurisdiction of the United States.

T2V events generally fall into the following categories:

Terrorism
Premeditated hate crimes
School-based targeted violence
Workplace targeted violence
Public mass violence
Other targeted violence (e.g., property crimes targeting critical infrastructure or key resources).

With the exceptions of public mass violence and other targeted violence, these categories are not mutually exclusive. For instance, an act of terrorism can also be coded as a premeditated hate crime.

The "public mass violence" and "other targeted violence" categories are only used if an incident does not fall into one of the other event types. For example, an act of terrorism that results in mass casualties would not be coded as "public mass violence" in the T2V data but rather the event would be coded simply as "terrorism."

The T2V data do not include:

Events that are (1) solely the result of gang activity, organized crime, or interpersonal/intimate partner violence, (2) crimes with a purely financial motive, or (3) hate crimes that were spontaneous or otherwise unplanned by the perpetrator prior to the event.
Incidents in which a perpetrator made a threat of violence but did not engage in at least one activity that indicates they were preparing to act on the threat. Similarly, an incident in which an individual was arrested for possessing a weapon, but the individual did not issue a threat or identify a target for a potential attack, would not be included in the data.
Events that are described as "hoaxes" or "not credible" by law enforcement or other officials with detailed knowledge of the events.
Events in which there was no potential for victims to be hurt or killed, or property to be destroyed, such as financial crimes (e.g., tax evasion).
Attacks on property that did not have the potential to destroy the functionality of the target or render it inoperable (e.g., graffiti, breaking windows, etc.).

Yes, the T2V data include violent plots that were foiled by law enforcement during their planning stages. For a foiled plot to be included in the T2V data, there must be evidence that the perpetrator(s) identified a potential target or targets for the attack and engaged in at least one mobilization activity in preparation for committing the crime. Evidence of mobilization is derived primarily from court records, including affidavits written in support of criminal complaints, indictments, and memoranda written in support of pretrial detention, plea agreements, and sentencing.

Mobilization indicators include:

target surveillance
military-style training
weapons acquisition
weapons assembly
financing
securing transportation to and from an attack site
forging identification documents
recruiting others to participate in or aid the attack
preparing manifestos or other legacy tokens to be released before or discovered after the attack
other planning activities.

The T2V data do not include incidents in which a perpetrator made a threat of violence but did not engage in at least one activity that indicates they were preparing to act on the threat. The T2V data do not include events that are described as "hoaxes" or "not credible" by law enforcement or other officials with detailed knowledge of the events.

Yes, the T2V data include failed attacks. Failed attacks are defined as premeditated incidents in which the perpetrators attempted but failed to successfully deploy weapons due to technical malfunctions or operational errors (e.g., an explosive device was planted at or near a target but failed to detonate).

The T2V database defines a successful incident as one in which the perpetrator(s) of the crime deployed a weapon (i.e., fired a gun, detonated an explosive device, ignited a fire, etc.) against a target. Success is not defined in terms of the perpetrator's tactical or strategic goals. For instance, an event in which a perpetrator detonates an explosive device in a building, but fails to hurt or kill anyone, would be coded as a successful attack even if the assailant's goal was to cause mass casualties.

Mass violence is defined in the T2V database as an event in which the perpetrator intended to commit, or committed, an attack resulting in four or more casualties (deaths or injuries). Attacks involving the (planned) use of non-lethal weapons (pellet guns, smoke grenades, etc.) are not coded as mass violence unless they were deployed in an attack and caused four or more injuries.

Following the standard established by the Global Terrorism Database, "Incidents occurring in both the same geographic and temporal point will be regarded as a single incident, but if either the time of occurrence of incidents or their locations are discontinuous, the events will be regarded as separate incidents." Individual events are flagged in the T2V data if they are part of a string of attacks committed by the same perpetrator(s). A foiled plot is treated as separated incidents if the plan involved attacking multiple discrete targets. Including these plots and attacks as separate incidents in the T2V data allows for the accurate coding of the locations and targets of violent events in the United States.

Yes, the T2V data include terrorist attacks that meet the Global Terrorism Database's definition of terrorism: "the threatened or actual use of illegal force and violence by a nonstate actor to attain a political, economic, religious, or social goal through fear, coercion, or intimidation." For more information, see the GTD codebook at http://apps.start.umd.edu/gtd/downloads/Codebook.pdf.

The T2V data include hate crimes that:

Meet the Federal Bureau of Investigation's definition of hate crime: "criminal offense against a person or property motivated in whole or in part by an offender's bias against a race, religion, disability, sexual orientation, ethnicity, gender, or gender identity."
Meet the T2V inclusion criteria described above.
Display clear evidence that the perpetrators of the crimes selected their targets before committing the attacks.

Hate crimes that are spontaneous, unplanned, or occur after chance encounters are not included in the T2V data. Moreover, hate crimes that do not involve the potential for violence (e.g., vandalism, denial of housing, etc.) or harm to property to such a degree to render the property physically inoperable are not included in the T2V data.

Yes, the T2V data include violent or potentially violent events that occur at educational institutions as long as:

They meet the T2V inclusion criteria discussed above.
They were premeditated and planned.
And they were not the result of organized crime, gang activity, or interpersonal or intimate partner conflicts.

School-based violent incidents related to interpersonal disputes are not included in the T2V data unless the events had a direct impact on a population beyond the intended targets of the attacks. For instance, fights between students on school property are generally not included in the T2V data. However, students who plan to commit, or commit, mass casualty attacks as revenge for being bullied are included in the T2V data.

Yes, the T2V data include violent or potentially violent events that occur at places of work as long as:

They meet the T2V inclusion criteria discussed above.
They were premeditated and planned.
And they were not the result of organized crime, gang activity, or interpersonal or intimate partner conflicts.

Yes, the T2V data include attacks targeting the 16 critical infrastructure sectors identified by the Cybersecurity and Infrastructure Security Agency, as well as vital community resources, such as schools and places of worship.

The T2V data only include attacks on critical infrastructure or key resources if:

They meet the T2V inclusion criteria above
They had the potential to destroy or otherwise render the infrastructure and resources unusable.

Vandalism or other crimes that did not disrupt the functionality of the infrastructure are not included in the T2V data.

Yes, the T2V data include attacks on places of worship, such as churches, mosques, and synagogues, as long as they meet the T2V inclusion criteria above and had the potential to physically harm people inside the facilities and/or to render the property unusable. Places of worship are considered key community resources in the T2V data, and thus we err on the side of inclusion when they are targeted in criminal events, even if source materials do not provide or confirm the exact motives for the crimes.

The T2V database does not include violence that occurs at protests or demonstrations unless there is clear evidence that the perpetrators of the violence planned the attacks prior to attending the events. For instance, a physical assault that follows an argument between protesters and counter-protesters would not be included in the T2V data. However, an incident in which an individual plans to attend a protest or demonstration for the expressed purpose of committing a violent attack would be included in the database. In some cases, premeditation is determined based on the perpetrators' statements or the results of criminal investigations into the events. In other cases, premeditation is inferred from the types of weapons used in the acts (e.g., events are assumed to be premeditated when the perpetrators of the attacks use explosive devices or other complex weapons that require assembly).

The T2V database does not include events that were result of interpersonal or intimate partner disputes unless those incidents also impacted victims who (1) were not participants in the disputes or (2) did not have prior relationships with the perpetrators of the attacks. For example, if a perpetrator were to target their romantic partner at their place of work and their partner was the only victim in the attack, the incident would not be included in the T2V data. If, however, a perpetrator targeted a romantic partner at their place of work and also attacked their partner's co-workers, resulting in a mass casualty event, the incident would be included in the T2V data.

The T2V data dashboard currently provides users with a descriptive summary of all events, as well as coded information on dates, locations, outcomes (i.e., successful attack, foiled plot, and failed attack), weapon types, number of perpetrators, ages, and casualties (total deaths, total injuries, perpetrator deaths, perpetrator injuries, victim deaths, and victim injuries). Future iterations of the dashboard will include additional variables related to target types and more.

A value of -99 in the T2V data indicates that researchers were unable to find information in public sources for a specific variable related to the event.

Currently, the T2V data are not available for download through the T2V data dashboard. This functionality will be added to the tool in the coming months. To request the raw T2V data, please contact us at t2v@umd.edu.

All inquiries about the T2V project can be sent to t2v@umd.edu.

Yes, we encourage researchers, analysts, scholars, and journalists to use the T2V data in their work. Use of the data signifies your agreement to our Terms of Use, which include properly citing the T2V database and refraining from redistributing or republishing the data for commercial or non-commercial uses. Using the T2V data for commercial purposes is a violation of the project's Terms of Use.

No, using the T2V data for commercial purposes is a violation of the project's Terms of Use. A license must be obtained to use the T2V data for commercial purposes. Please contact t2v@umd.edu to inquire about licensing the data for commercial use.

No. Users should not infer any additional actions or results beyond what is presented in a T2V entry. Specifically, users should not infer an individual associated with a particular incident was tried and convicted of terrorism or any other criminal offense. If new documentation about an event becomes available, an entry may be modified, as necessary and appropriate.

Yes. Please use the following citation if using the T2V data in your own research/ publication:

National Consortium for the Study of Terrorism and Responses to Terrorism (START). (2025). Terrorism and Targeted Violence (T2V) in the United States [Data file]. Retrieved from https://www.start.umd.edu/t2v