Are public surveillance cameras a good idea? More cities are monitoring their streets and public spaces.

• Position: Debate

YES

Within hours of the Boston Marathon bombing last April, authorities began sifting through video surveillance footage. These images, along with cellphone videos, proved instrumental in quickly identifying two suspects and capturing them before they could carry out any more attacks.

This case demonstrates how effective surveillance cameras can be in keeping the public safe. Many buildings already have private security cameras that cover surrounding public areas, capturing images that can be shared with law enforcement. Installing more public safety cameras simply enhances our ability to protect people.

In San Francisco, crimes such as burglary and vehicle break-ins declined 30 percent in areas where cameras were installed, and many cases, including homicides, have been solved by analyzing video footage. In Denver, authorities use public surveillance cameras during storms to determine where emergency help is needed.

Opponents argue cameras invade privacy and police may use them to target innocent people. To address these concerns, we have rules in San Francisco requiring cameras to be aimed only at public spaces, never private places. Plus, we're not allowed to monitor cameras in real time; they are used after the fact, as an investigative tool. And they're turned off during protests and other events involving freedom of speech.

The benefits of the responsible use of cameras far outweigh the risks of possible misuse. When a tool such as a camera can keep people safe, it makes sense to use that tool to its maximum effectiveness.

--GREGORY P. SUHR

Chief of Police, San Francisco, California

NO

The benefits of surveillance cameras are often exaggerated and their drawbacks ignored.

Surveillance cameras don't stop terrorist attacks. They can be helpful in solving an attack afterwards, as they were in Boston, but even that benefit can be overblown. When a...