Twenty-three officers from the New York Police Department (NYPD) were killed during the terrorist attacks on September 11, 2001. The NYPD is integrating counterterrorism training to include every uniformed police officer and precinct detective. They are required to participate once a year in the 2-day training program designed to help officers brush up on their policing skills, as well as introduce them to new tactics and strategies. All of the sessions are taught by police officers. In-Tac training is held 5 days a week in nine different locations throughout the city’s five boroughs. The training is incremental. About 300 to 500 officers are trained a week. The first day exposes officers to real-life scenarios, such as car stops. The second day consists of intensive classroom instruction, now devoted entirely to counterterrorism tactics. The NYPD is emphasizing to its officers the importance of eternal vigilance in light of how bits of unrelated information can sometimes lead to foiling a terrorist plot. The real-life scenarios that are part of the In-Tac program are a series of highly stressful policing situations. Following these exercises, an In-Tac instructor evaluates the performance of the police officers. A full-day session on terrorism is divided into three units, including the history of foreign and domestic terrorism in the United States, the terrorist mindset and mission, and counterterrorism tactics. The officers are instructed to be alert on the street, be aware of world events, and try to become better acquainted with the members of the community. Prevention tactics include detecting fraudulent documents, potential explosive devices, and hazardous material. About 70 percent of terrorist incidents have involved the use of explosive devices.