CCTV footage showed a property in the Hartcliffe area of Bristol being attacked at approximately 10pm on January 27.
Three people were seen outside with machetes, with bricks thrown through a window and a woman left injured.
The footage is a precursor of the attack from which a 15-year-old boy has admitted murdering one of two teenagers who were attacked in a case of mistaken identity, a jury was told.
The defendant, who cannot be named because of his age, accepts that he killed Mason Rist, also 15, by inflicting at least one of two fatal injuries during the attack in Knowle West on January 27.
Another boy, who is now 17 years old and also cannot be named, has admitted the manslaughter of Mason’s friend Max Dixon, 16.
They are among five people who are on trial at Bristol Crown Court charged with murdering Mason and Max.
