(CBS) NEW YORK - Last month, New York City announced the indictments of 49 members of two neighborhood gangs called "Very Crispy Gangsters" and "Rockstarz" on charges including murder, attempted murder and conspiracy. How did the department build the cases? They got online.
"By capitalizing on the irresistible urge of these suspects to brag about their murderous exploits on Facebook, detectives used social media to draw a virtual map of their criminal activity over the last three years," New York City Police Commissioner Raymond Kelly told attendees at the annual conference for the International Association of Chiefs of Police last week.
According to the Associated Press, one suspect from the Rockstarz crew allegedly posted "Rockstarz up 3-0," in apparent reference to three people killed in a turf war between the Brooklyn-based groups.
Fresh off the Very Crispy success, Kelly announced last week that he was doubling the size of the city's gang squad and placing a specific focus on having officers monitor Facebook and other social media sites to try and curb gang crime.
Kelly and the NYPD are not alone. Jeremiah Johnson, a computer crimes specialist with the National White Collar Crime Center, says that more and more police departments are requesting training on how to use open source social media in their investigations. According to a survey released in late September by the International Association of Chiefs of Police, 74 percent of the 600 law enforcement agencies that responded to the IACP survey said they have already used social media to help solve crimes in their jurisdictions.
"People in gangs will put things up on the internet that they wouldn't even tell their most trusted lieutenant in the organization...It's really surprising the open discussion about drug trafficking, human trafficking, weapons, robbery," says Chuck Cohen, a lieutenant with the Indiana State Police who is also an expert on using social media in criminal investigations.
For years, Cohen has traveled the country training police departments large and small on how to use social media to track criminal activity. From posing with weapons on Facebook, to live-streaming video of drug use on Stick-Am, to chatting about criminal exploits in the comments section of a YouTube video, Cohen says that gang members and other criminals leave an electronic trail. They also geo-tag images, use chat logs and have multiple online monikers.
Sometimes, says Cohen, the starting point for an investigation is a seized cell phone, which gives law enforcement user information for a suspect's Facebook page. Once they log on, officers can connect to other gang members, sometimes by creating their own false profile, thus obtaining access to images and conversations that might later be useful as evidence.
Or, says Cohen, an informant might tip police off that instead of hanging out at a neighborhood bar or on the corner, gang members hang out and chat on Xbox Modern Warfare.
In order to help law enforcement capture more social media activity, the National White Collar Crime Center announced in July that they are adding a new software called "X1 Social Discovery" to their social media training. According to Johnson, X1 Social Discovery allows law enforcement to input online monikers from various sites - like Facebook, MySpace and Twitter - and the software will scan for updates on those accounts.
Even though some gang members - like those in the street crews rounded up last month by the NYPD - may "feel anonymous online," Johnson warns that officers have to have some tech savvy themselves to keep up.
"You have to dedicate a lot of time to building a profile," says Johnson. "If they see your profile has just two days of action, a gang member is going to think, 'I don't trust that.'"
And just like gathering information on the street, speedy evidence collection and preservation is crucial.
"I tell officers, when you see it, preserve it now, because when you refresh your browser it could be gone," says Cohen.
And it's that kind of speed and agility that Cohen says is necessary to keep up with the ever-evolving world of online communication.
"Every time I do a training I have to update my information," says Cohen. "The way people choose to communicate is evolving over time -- it's a matter of law enforcement evolving with them."