Not since O.J. Simpson raced down the freeway in his white SUV in 1994, has the nation monitored a manhunt such as the one underway in Watertown, Mass., for one of the two named suspects in the Boston Marathon bombings.
But the ways we watch have changed. The Internet has brought live video feeds from local stations and national networks onto computers and mobile devices around the world. Reporters are tweeting. A Watertown resident is doing an AMA (ask me anything) on social news site Reddit as SWAT teams take up positions on his street. Another Redditor is live-mapping the manhunt, using various markers on Google Maps to show where events take place as they happen.
And thousands of people have tuned into police scanners to hear firsthand the chatter between law enforcement personnel as they coordinate their operation. Streams from scanners that have tapped into law enforcement channels are available from a variety of websites, including Broadcastify and Ustream, as well as from several mobile apps, such as Scanner911 and 5-0 Radio, both free from the App Store, and Scanner Radio for Android in Google Play.
Scanner apps, like their Web-based counterparts, allow users to choose a channel from 100 or more available channels. Most lists are arranged by current number of users, so it's easy to find the channel that others have found most useful. Scanner911 constantly records a broadcast and lets users save 15-second snippets as they listen, which can then be shared to Twitter or emailed as a link. (But sharing could get you into trouble. More about that later in the story.)
Listening to a scanner broadcast is a riveting experience for the listener, but can be disturbing.
"Just listening to the police scanner last night creeped me out all the way in Pennsylvania, so I can't begin to imagine how you must have felt listening to them talk about your own neighborhood," a Redditor hellapr0per wrote. [See also: Reddit Doing CSI-Worthy Investigation of Boston Bombings ]
The public nature of the information also can pose problems for law enforcement. Information heard on scanners has made it to all major social media sites, including Twitter, Reddit, Tumblr and Facebook. Boston police have told media not to disclose location information.
#MediaAlert : WARNING: Do Not Compromise Officer Safety by Broadcasting Tactical Positions of Homes Being Searched. — Boston Police Dept. (@Boston_Police) April 19, 2013
Likewise, Reddit has requested that those providing live updates on the social news site, remove any posts that contain information about police movements.
Some scanners shut down their broadcasts as the situation intensified. But as soon as one was shut down, alternative sources were recommended on social media feeds. Some law enforcement agencies switched to encrypted channels to prevent the public from listening and then sharing critical communications.
Although listening to unencrypted police channels from home scanners is legal in most states, using a mobile scanner is illegal in some. Using a scanner app on a smartphone (essentially turning the device into a mobile scanner) is against the law in some states, such as Indiana. If you decide to listen in, don't post information that is broadcast over these channels.