A man is in custody following an incident at a pharmacy on Fitzgerald Street in Northam on Sunday morning.
The 36-year-old Northam man was arrested just after 9.45am following reports that he had allegedly entered the store with a knife.
A 63-year-old man was also located nearby with a wound to his back.
He was convey by St John Ambulance to Northam Hospital for treatment.
Northam Detectives are investigating.
Anyone with information is asked to call Crime Stoppers on 1800 333 000 or to make a report online at crimestopperswa.com.au.
Further information to come.