Pulse Nightclub Shooting

The June 2016 shooting spree at the Pulse nightclub in Orlando, Florida, by Omar Mateen—who killed 49 people and wounded 53 more—dwarfed in its lethality all other extremist-related murders in the decade. Mateen, who claimed his attack in the name of ISIS, though there were no known connections between him and that terror organization, achieved the dubious distinction of being the deadliest domestic terrorist since Timothy McVeigh bombed the Murrah Federal Building in Oklahoma City in 1995.

This database provides an overview of many of the terms and individuals used by or associated with movements and groups that subscribe to and/or promote extremist or hateful ideologies.

Yahya Sinwar

Yahya Sinwar, widely known as the architect of the October 7, 2023, massacre in Israel, was a key Hamas leader who served as the Gaza Political Bureau chief from 2017 until July 2024 and organization-wide Political Bureau... Read more

People Islamist

Hate Group

An organization whose goals and activities are primarily or substantially based on a shared antipathy towards people of one or more other different races, religions, ethnicities/nationalities/national origins, genders, and/or sexual identities. The mere presence of bigoted members... Read more

Key Concepts / Definitions White supremacist

Colleyville Synagogu…

On January 15, 2022, a gunman entered Congregation Beth Israel in Colleyville, Texas, during services, taking three congregants and a rabbi as hostages. The standoff ended more than ten hours later with all hostages released, unharmed, and... Read more

Incidents / Events Islamist

Aafia Siddiqui

Siddiqui is a Pakistani woman who studied neuroscience at Brandeis and MIT in the 1990s and returned to Pakistan in 2003. She allegedly worked as a courier and financier for Al Qaeda. She was taken into custody... Read more