DETECTIVES have charged a 35-year-old Butler man after an investigation into four incidents in Butler and Perth earlier this month.
The man was due to appear in the Perth Magistrates Court on Friday, January 13.
A WA Police spokesman said regional investigation unit detectives will allege about 11am on Saturday, January 7 the man entered a business premises on Butler Boulevard in Butler.
They will allege the man was removing a cash tray when disturbed by a staff member and that he produced a knife, threatening the staff member with it before running from the store.
The detectives will also allege about 12.45pm on Tuesday, January 10 the man entered a business premises in Murray St, Perth and produced a knife while demanding cash from the employee.
The man was handed an amount of cash before he left the store.
The spokesman said about 12.50pm the same day the Butler man entered a business premises in Wellington Street Perth.
Detectives will allege the man demanded cash from the till but the staff member refused to hand over any cash.
A second employee walked towards the man, so the man grabbed a mobile phone on the counter and left the store.
Finally detectives will allege about 3.45pm on Thursday, January 12 the same man entered a business premises on Wellington St, Perth and produced a knife, demanding cash from the employee.
After being told there was no cash, the man grabbed a mobile phone on the counter and left the store.
The Butler man was charged with one count of aggravated armed robbery and three counts of armed robbery.