A woman and a man were shot inside the Pimentel Market on Centre Street at Wyman Street around 2:45 p.m.
First responders found the woman at the store, but the main fled before they arrived. He turned up later at a local emergency room.
On Twitter, Maul Panafort reports hearing about six shots.
It's the second shooting inside a store in Jamaica Plain in several days. On Saturday, a man was fatally shot inside the Professional Barber Shop on South Street.