Wanneroo man Ryan Mathew Boudville is believed to have died of stab wounds at the scene after police were called to a Dericote Way home about 3.45am on August 8.
Police believe Mr Boudville (32) was known to occupants of the home and had attended the property with a number of other people who fled when the situation became volatile.
Major Crime investigators spoke with residents but released them without charge on Monday.
Police wish to speak with witnesses who saw anyone leaving the Dericote Way area by foot or by vehicle just before 4am on Saturday.
Call Crime Stoppers on 1800 333 000.