Three men who assaulted an elderly Tokoroa couple went to a party afterwards and boasted about what they had done, police say.
The attack last Thursday left 73-year-old Bob Gabolinscy with a gash to his head and his 75-year-old wife Margaret with a black eye and bruising to her face.
The officer in charge of the case, Sergeant Terry Garnett, said three men in their teens and early 20s are believed to have been involved in the attack in an alleyway neighbouring the Gabolinscys' home.
The three are believed to have been at a party in the Balmoral Drive area before the attack, and to have gone on to another party afterwards.
"At the second party they spoke about the incident and we are trying to find some people who could come forward in relation to that.