Compared to most types of criminal violence, terrorism poses special data collection challenges. In response, there has been growing interest in open source terrorist event databases. One of the major problems with these data bases in the past is that they have been limited to international events—those involving a national or group of nationals from one country attacking targets physically located in another country. Past research shows that domestic incidents greatly outnumber international incidents. In this paper we describe a previously unavailable open source data base that includes some 70,000 domestic and international incidents since 1970. We began the Global Terrorism Database (GTD) by computerizing data originally collected by the Pinkerton Global Intelligence Service (PGIS). Following computerization, our research team has been working for the past two years to validate and extend the data to real time. In this paper, we describe our data collection efforts, the strengths and weaknesses of open source data in general and the GTD in particular, and provide descriptive statistics on the contents of this new resource.
LaFree, Gary, and Laura Dugan. 2007. "Introducing the Global Terrorism Database." Terrorism and Political Violence 19 (May): 181-204. http://ccjs.umd.edu/sites/ccjs.umd.edu/files/pubs/FTPV_A_224594.pdf