|One or more security cameras to monitor the school||—||38.5||47.9||57.9||66.0|
|Security guards and/or assigned police officers||54.1||63.6||69.6||68.3||68.8|
|Other school staff or other adult supervision in the hallway||85.4||88.3||90.6||90.1||90.0|
|A requirement that students wear badges or picture identification||—||21.2||22.5||24.9||24.3|
|A code of student conduct||—||95.1||95.3||95.5||95.9|
|Locked entrance or exit doors during the day||38.1||48.8||52.8||54.3||60.9|
|A requirement that visitors sign in||87.1||90.2||91.7||93.0||94.3|
|— Not available.|
NOTE: Data for 2005 have been revised from previously published figures. “At school” includes the school building, on school property, on a school bus, and, from 2001 onward, going to and from school. In 2005 and 2007, the unit response rate for this survey did not meet NCES statistical standards; therefore, interpret the data with caution. For more information, please see appendix A.
SOURCE: U.S. Department of Justice, Bureau of Justice Statistics, School Crime Supplement (SCS) to the National Crime Victimization Survey, various years, 1999–2007.