From behind bars, Juan Guzman ran a multimillion-dollar drug ring with the help of his sister, a state employee, providing cocaine from Mexico to the streets of Boston, according to authorities. On Monday, their enterprise was brought to an end by the largest drug ­investigation in the city in at least a decade.

Fourteen people were arrested just after dawn by about 100 Boston police officers and FBI agents in 12 locations across Boston, Milton, and Canton, dismantling an illegal operation that authorities likened to the television show “The Wire.”