A police cordon, including armed officers, is protecting the scene this morning.
What appears to be blood stains can be seen on the front door frames.
Locals say the occupants have only been living at the address for a few months.
"There was always a lot of cars coming and going," one resident said.
"You never expect this is your street. It's awful."
A scene examination was to take place this morning and the home is under police guard.
Police were seeking information about a 1998 purple Honda Accord, registration XC4771 and a black Subaru station wagon.
People were warned to not approach either vehicle but call 111.
If people had concerns or information to help with the investigation they can contact Christchurch Central Police Station on (03) 363 7400 or anonymously on 0800 555 111.