The General Secretary of the Papua New Guinea Catholic Bishops' Conference, Lawrence Stephens, says PNG police uses force far too liberally.
This comes after a shooting between police and four civilians occurred last Saturday in the capital, Port Moresby.
According to police one person is hospitalised, the other three are in police detention.
Mr Stephens says the shootings would have been avoidable.
"A vehicle, apparently stolen, passing past the old national parliament in Port Moresby went through a roadblock, the driver jumped out and was shot as he tried to escape, a passenger was shot while he was lying on the ground and two passengers were knocked to the ground and shot through the legs."
But a spokesperson for the police in Port Moresby says the officers were only defending themselves after the men being pursued had fired at them.
Police in PNG have frequently been criticised by international agencies for their excessive use of violence.