I didn't see any follow-up, so I assume so got away with the heist. Between 1914 and 1924, doctors could prescribe opiates, so that explains the presence of the drugs. The pharmacy was in Hyde Square, at the current location of a tattoo shop. Just goes to show that drug crimes didn't begin in the 1960s.
Boston Globe March 31, 1917
Mysterious Drug Woman Eludes Police Chase
The mysterious young woman who "cleaned up" 30 grains of morphine sulphate, 30 grains of hydrochlorate of morphine, 20 grains of cocaine, 40 grains of heroin and half an ounce of powdered opium, at the pharmacy of William A. Lynch at 380 Centre st, Jamaica Plain, Thursday afternoon, was still at large at a late hour last evening, though the police have clews that may result in an arrest. The large amount and the variety of the narcotics taken is spurring on to a thorough canvass of West Roxbury by special officers.
The young woman entered the store and said she was ill. While the clerk was trying to assist her she swept off the drug shelf. The police secured a detailed description of the young woman.