North Perth attack: Good Samaritan injured after being assaulted while helping man on Alma Street

Detectives are probing a violent series of events that saw a good Samaritan allegedly slashed with a pair of scissors after he tried to help a hit-and-run victim lying injured on the road.

The incident unfolded on Alma Street about 5.30pm on Sunday after a 49-year-old man was hit by a white Toyota Camry. Police are still on the hunt for the driver.