Cannington Detectives are investigating a series of incidents including a violent robbery in Bentley on March 18.
About 9.20pm, a 60-year-old man, was sitting outside his place of work, at a warehouse on Ewing Street, when two men walked into the carpark.
One of the men looked into the warehouse and returned to the second man, handing him a rock.
The second man approached the victim at a close range and threw the rock at the mans head which caused him to fall to the ground.
The second offender searched the mans pockets and stole his wallet, phone and cigarettes while he was on the ground.
Both men then entered the warehouse, removed a number of items and fled in an vehicle.
The victim was taken to hospital with a broken jaw and facial swelling.
About an hour later, a dark coloured Ford Territory drove off from a fuel station without paying for petrol in Thornlie.
The Ford was was stolen from Erskine and was located the next day abandoned in Wilson.
Police have released a CCTV image of a man who they believe may be able to assist them with their investigation into these incidents.
Please quote Reference Number 9198.
You can remain anonymous if you wish and rewards are available once charges are laid.