Sean Favors is under arrest, charged with robbery and assault.
Prosecutors say he used a hammer to attack the 77-year-old homeowner Bong Ho Park on the 600 block of Wyndrise Drive in Blue Bell.
Park and his wife own a business in Philadelphia. Two other suspects forced Park's wife to get cash from inside the home.
Authorities believe the men followed the victims home.
Favors is in jail on $250,000 bail.
No word if the other suspects were also apprehended.