A young man’s bail on two open drug cases was revoked yesterday following his arraignment on charges that he kept a loaded semi-automatic pistol and 22 bags of marijuana in his bedroom, Suffolk County District Attorney Daniel F. Conley announced.

JONATHAN LEON (D.O.B. 7/2/91) of Jamaica Plain was arraigned in West Roxbury District Court yesterday and charged with unlawful possession of a firearm, unlawful possession of ammunition, improper storage of a firearm, possession of a Class D drug with intent to distribute as a second offense, and violating the state’s drug laws within 1000 feet of a school.

District Court Judge Shannon Frison ordered Leon held on $15,000 cash bail. Frison granted Assistant District Attorney Christopher Meade’s motion to revoke Leon’s bail on three pending cases, two of which also allege possession of a Class D substance with intent to distribute.

Meade told the court that Boston Police detectives executed a search warrant at Leon’s residence just before 2:00 on Friday afternoon. Based on information developed in the course of their investigation, the detectives believed Leon to be an associate of Boylston Street gang members with illegal drugs in his home.

Upon arrival at Leon’s Boylston Street home, the officers knocked on the front door, announcing their presence and the search warrant. After announcing themselves three times and hearing what sounded like a person moving inside, officers forcibly entered the home.

After entering, officers encountered the defendant, ordered him to the ground, and read him his Miranda rights. During a search of Leon’s bedroom, officers recovered a FEG AP9 .380 caliber semi-automatic pistol loaded with five rounds of ammunition, one additional .380 caliber round of ammunition, two plastic bags containing a total of 18 individually wrapped plastic sandwich bags of marijuana, $158 in cash, a marijuana grinder, and a digital scale.

Detectives also recovered a $100 bill believed to be counterfeit. Leon may face additional charges in connection with that bill at a later date.

Police seized an additional four sandwich bags containing marijuana, a cell phone and $20 in cash from Leon’s person following his arrest.

Leon is represented by attorney Amy Jo Freedman. He is expected to return to court on September 16 for a pre-trial hearing.