Boston police have arrested a 15-year-old boy with a loaded firearm and located a missing 14-year old in Dorchester. The arrest was made following a department-wide notification of a missing juvenile believed to be in possession of a firearm. The missing 14 was also found safely and returned to his guardians. Although no firearm was recovered, police became concerned about the behavior of another juvenile in the group. The boy was taken into custody and charged with various charges including unlawful possession of firearms, ammunition violations, and a defaced serial number.