A Danbury man has pleaded guilty to possession of a firearm during a drug trafficking crime.  The arrest stemmed from a drug sale in Stamford in September.  The U.S. Attorney's Office says Police searched a backpack belonging to 28-year old Fernando Rodriguez and found 58 grams of cocaine and 116 grams of marijuana.  A search of a secret storage compartment in his car turned up  an additional 100 grams of cocaine, a 9mm handgun, and a loaded 9mm magazine.  Rodriguez has been detained since his federal arrest on January 10th and he is set to be sentenced June 7th.  Rodriguez faces a mandatory minimum term of five years in prison and a maximum term of life.