"He's (the offender) walked in, one of the victims has found him and the other victim returned home ... and then he's (the offender) carried out this ghastly deed."
Mr Burke said the man attempted to tie the couple up with clothing, threatened them with a knife and stole their car.
"As you'd expect they're bloody traumatised," he said.
Mr Burke said police were not dismissing the possibility that more than one person may be involved.
Police found the couple's red 2011 Ford Mondeo in Puketona, south of Kerikeri, yesterday about 1.10pm.
Police want to hear from anyone who saw the red Ford Mondeo in Whangarei or Kerikeri between 3.30pm Tuesday and 1.10pm.
Mr Burke said they are also seeking witnesses who saw a white saloon which crashed near the intersection of Three Mile Bush and Church Road on Tuesday.
"The car was travelling at speed and crashed into a stone wall. If anyone saw who the occupant of the vehicle was they should contact police"
Mr Burke said police believed the person involved in the crash may have abandoned the vehicle and subsequently stole the car from the victims.
"This is a completely unprovoked attack which beggars belief and this offender needs to be caught," he said.
Mr Burke said no other items were taken from the couple's home.
Yesterday police carried out a scene examination of both the area of the crash and the victims' home. Mr Burke said two people were assisting the police with their investigation.
Any person with any information is asked to contact the Whangarei police on 09 4304500 or Crimestoppers anonymously on 0800 555 111.
