Detectives have charged a fourth person over an aggravated burglary at an apartment in Halls Head.
It is alleged the 35-year-old man was one of several people who entered the property on Apollo Place on August 8, and once inside they assaulted the two occupants before stealing various items.
A 23-year-old woman received minor injuries and a 24-year-old man was taken to Peel Health Campus with a cut to his head and an arm injury.
The Madora Bay man has been charged with aggravated burglary and commit, aggravated armed robbery, possessing a prohibited drug and possessing drug paraphernalia.
He is next due to appear in the Perth Magistrates Court on September 9.
A 20-year-old woman and a 36-year-old man both from Coodanup and a 31-year-old man from Greenfields were charged over the incident last week.
Scorching Christmas temperatures for Perth, Rockingham, Mandurah
Teen charged over Baldivis arson attack
Concerns for missing boy last seen in Warnbro
Baldivis Sports Complex officially complete with unveiling of final stage
Teen dies at Logue Brook Dam
Mandurah named WA’s Most Accessible Community
Police attend separate crashes in Lakelands and Port Kennedy
Fresh new look for Roger May Machinery Museum
Tragic end to search of missing FIFO worker