At least that’s the impression one can’t help but get from statistics released by the Federal Bureau of Investigation in late May. Violent crime, according to the FBI, decreased 5.5 percent from 2008 to 2009 – the third straight year it has declined and the biggest drop since the 1990s – while property crime dipped 4.9 percent. Arson, which is not included in either category, dropped 10.4 percent.

The improvements were most noticeable in major urban areas. In cities with populations of 1 million or more, violent crime dropped 6.9 percent and property crime 7.9 percent, while in those with populations of 500,000 to 1 million, violent crime decreased 7.5 percent. In both of these groups of cities, murders plunged more than 11 percent and robberies dropped nearly 10 percent.

So, why is crime decreasing? We haven’t seen major demographic, cultural or socioeconomic shifts that might explain it. In fact, the biggest event affecting U.S. society in recent years has been the economic downturn, and conventional wisdom holds that crime usually increases during a recession.

Researchers do not seem to have a firm idea of what is behind the decline, but a few possibilities that have been mentioned include improved police work and increased funding through the 2009 economic stimulus bill for law enforcement. While having more and more effective police officers were almost certainly important factors, I would like to suggest one other possible explanation that seems to have been overlooked in much of the reporting about these statistics: Security technology is improving and becoming much more widespread.

Take the humble video camera. Just a few years ago, it would provide its user with a videotape of probably grainy, black-and-white footage. Now, a state-of-the-art camera offers high-definition digital video that can provide a sharp picture even in low-light conditions and that can be combined with video analytics to immediately alert security personnel and law enforcement to suspicious activity.

Access control for buildings, meanwhile, has experienced similar advances, with IP connections, biometrics and other technology locking down facilities to would-be intruders and sounding the alarm if unauthorized entries are attempted.

These improvements in security technology – along with countless others throughout the industry – have three important effects. One, they deter crime. Two, certain devices, such as access control mechanisms, provide an active defense against attempted criminal acts. And three, if a crime is committed, security components provide a wealth of information that can be used by the authorities to catch and incarcerate the perpetrators.

As the effectiveness of security products has increased, so has its utilization rate. The Security Industry Association’s U.S. Security Market Report released in 2009 found not only that the security market has been growing but that it is projected to continue to expand. At the time of the report’s publication, about half of the country’s non-residential facilities had access control and video surveillance systems while three-fourths had intrusion/fire detection systems. For each of these technology categories, about half of those who did not have the equipment indicated that they planned to have it within five years.

None of this, of course, is meant to diminish the performance of police officers or their obvious role in reducing crime. At its best, security equipment is a complement to law enforcement, providing both an early warning system and an important source of evidence. The improved functionality and increased use of hi-tech security solutions has enabled these devices to be more effective tools both for end-users and for police, and this may be one of the most important – and largely unseen – reasons why we are safer now than we have been in a long time.