OAKLAND, Calif. (KTVU) - Facebook postings by a suspected gang member has helped ATF (Bureau of Alcohol, Tobacco, Firearms and Explosives) put an Oakland man behind bars.
Law enforcement says social media is now commonly used by investigators to help solve crimes.
Zack Tutu Mapp is is in federal custody and is being held at the Glen Dyer Jail near Oakland Police headquarters.
ATF tracked Mapp through Facebook. Federal agents say Mapp is suspected of leading a street gang that is responsible for a series of robberies.
In the criminal complaint obtained by KTVU, federal investigators detail how Mapp's online postings helped them build their case against him.
Agents found photos of Mapp, some showing weapons and money, along with messages boasting about his involvement in criminal activities written on his page.
"It gives us more information, helps us make better decisions, more accurate decisions," says Anthony Ribera, former San Francisco Police Chief.
He runs the Criminal Justice Institute at USF. Ribera says the internet is extremely helpful to law enforcement. that arming officers with smartphones and laptops help solve crimes.
"A lot of people who engage in criminal activity don't think they'll get caught. Eventually people's luck runs out, particularly if they're sharing information," says Ribera.
In this case, agents compared Mapp's booking photos from previous arrests in Alameda County to his online photos to confirm that Mapp is the suspect.
ATF raided Mapp's home in East Oakland late last month, using the online postings to secure a search warrant.
Mapp was arrested. The agency seized a gun and ammunition, which led to a grand jury indictment.
"They got a warrant from a judge based on probable cause. They did it the right way. I think it'll probably stand up in court and they'll do well," says Ribera.
Mapp faces up to 10 years in federal prison for illegal gun possession. There is no bail.
Law enforcement officials say in the past 15 years, social media has helped them solve various crimes from recovering stolen items to homicides.