Milford police arrested a West Haven man on a warrant Wednesday, charging him with robbery and assault on an elderly person in connection with a July 25 purse snatching. Police say that Joshua Gray, 28, of Contact Drive in West Haven is accused of snatching a purse from a woman in the parking lot at Barnes & Noble at 1375 Boston Post Road in July. The elderly woman suffered minor injuries from being dragged by the suspect, police said. Gray also is accused of stealing a purse from a car in the Adams parking lot at 1365 New Haven Avenue July 23. Bond was set at $50,000 for the assault, and $500 on the July 23 theft, and Gray was arraigned in court Wednesday.