Police have charged an 18-year-old man over an alleged home invasion in Barragup on Australia Day.
It is alleged a group of men, armed with golf clubs, knives and guns, stormed the home on Tranquil Retreat around 10.15pm on Saturday.
They allegedly assaulted the 47-year-old occupant, his 18-year-old son and his son's girlfriend.
All three victims suffered broken bones, cuts and bruises and were taken to Royal Perth Hospital for treatment.
On Monday, police arrested an 18-year-old Maddington man.
He has been charged with aggravated burglary, aggravated assault, intent to do grievous bodily harm and possessing a prohibited drug.
He was refused bail and is due to appear in the Perth Magistrates Court today.
The investigation is ongoing.
Anyone with information regarding this incident is asked to call Crimes Stoppers on 1800 333 000 or report the information online at www.crimestopperswa.com.au.