Police in San Juan are identifying the gangs by the way they dress, symbols they wear.
They say gang members are getting recruited to do street level jobs for Mexican drug cartels.
Gang members are muscle for hire. Kidnappings, home invasions, murders, they'll do anything to tap into the cartel's dirty dollars.
"A lot of money is going south into Mexico and everybody wants a part of that and street gangs also want a part of that," says San Juan Chief Juan Gonzalez.
Chief Gonzalez says having locals helps the cartels.
"They know the geographical area and they study as much as we study them. They have counter surveillance. They have individuals specifically targeting our communication systems," he says.
Everything from clothes, and symbols to tattoos are logged and categorized as markers for gang members.
A new way for authorities to fight Mexican cartels setting up on Valley streets.