The man and two other suspects were apprehended by the Lae police and will be facing charges related to the armed robbery.
The wounded suspect was identified as a man from Yangoru, East Sepik, while the other two are from Morobe Province.
They are all from the Miles area in Lae.
The Lae metropolitan superintendent, commander Anthony Wagambie Jnr, said the three men were part of at least a ten-man gang armed with machetes and home-made guns.
The group had attempted to rob the shop but they did not anticipate that the owner would have a pistol.