Privately owned surveillance cameras are increasingly providing leads to law enforcement during investigations, and police departments, such as the Williamson County, Texas, sheriff’s office, are encouraging the public to register their video surveillance cameras.

The past several months, more than any time in history, have highlighted the evolving role of surveillance in law enforcement, public safety and security.

A locked surveillance room, internal emergency call systems and a complex building layout led to initial confusion regarding the number and identity of perpetrators in the September 2013 Navy Yard shooting in Washington D.C.

According to a new local law, businesses in White Plains, N.Y., are now required to record quality video of patrons and provide that recording to police on demand. The law was passed last week unanimously by the Common Council, requiring certain merchants to install and maintain digital video camera systems to view and record quality video of everyone who enters.

The Oakland, Calif., City Council has voted 6-1 to move ahead with a controversial city surveillance center (the Domain Awareness Center), which would allow police and city officials to continuously monitor video cameras, gunshot detectors and license-plate readers across the city.

The Justice Network's facial recognition system now allows about 500 law enforcement personnel in Pennsylvania to access facial recognition databases from both the criminal justice system and the Department of Transportation.

Chicago's network of police cameras has proven more effective in reducing crime in high-crime areas than in low-crime neighborhoods.