GAITHERSBURG, Md. -- Police have arrested a man they say is responsible for at least two armed robberies of pharmacies in Montgomery County.

Douglas Vincent Minchillo, 46, was arrested yesterday evening and charged with two counts of armed robbery, four counts of first-degree assault, two counts of use of a handgun in a violent felony crime, and two counts of theft over $500.

Detectives said Minchillo robbed the Ambulatory Care Pharmacy, which is located in the 9700 block of Medical Center Drive in Gaithersburg. Authorities also said Minchillo robbed the White Flint Pharmacy located in the 11100 block of Rockville Pike in Rockville on Oct. 25 of last year.

Police said that on Feb. 11 at about 12 a.m. Minchillo entered the Ambulatory Care Pharmacy with an unknown object in his hand, announced the robbery and threatened to shoot the store employees. They said Minchillo then obtained Oxycondin and Percocet and fled the store.

Authorities also said that on Oct. 25, 2005, Minchillo entered the White Flint Pharmacy, displayed a gun wrapped in a plastic bag, and demanded Percocet and Vicodin and that he received bottles of the narcotics, which were valued over $500.