Police are asking Te Atatu residents to look out for blood on clothing and shoes that may have been put in public rubbish bins after the "vicious and prolonged assault" of 69-year-old Cun Xiu Tian on Friday.
She received multiple blows to the face and head, post-mortem results found on Saturday.
"Based on our scene examination, and the post-mortem results, we believe that it is highly likely that the people responsible for this have left the scene with blood on them, their shoes, their clothing or the person," says Detective Senior Sergeant Roger Small.
"The offenders may have attempted to wash themselves or their clothing, dispose or burn their clothing."
Ten more police officers have today joined the investigation team working to find the killer.
Ms Tian was found dead in her own home on Glenvil Ln in the Auckland suburb by her daughter and son-in-law on Friday evening.
Det Snr Sgt Small asks that residents of the area "be particularly vigilant around friends, family members, associates and flatmates that might have come home after 9am on Friday last week, that have behaved suspiciously, that have tried to dispose clothing or wash themselves".
Neighbours told media an ambulance, armed police, dog squads and a helicopter swarmed the area, causing a lockdown of the street.
Criminal profilers from the New Zealand police profiling unit arrived at the scene this morning to examine and assess the property where Ms Tian lived.
"Criminal profiling is something that we bring on board in most crime these days. They can build up a picture of how the offenders tick and operate, and what makes them do these violent crimes," says Det Snr Sgt Small.
Thousands of hours' worth of CCTV footage from the wider Te Atatu area is still being reviewed by investigators.
Det Snr Sgt Small confirmed today that detectives have spoken to 300 residents and 125 homes in the Te Atatu area.
He says the investigation team are looking into suspicious crimes in the area in the weeks and months leading up to Ms Tian's attack.
Det Snr Sgt Small says police understand the community is very shaken by the attack.
"This is an appalling crime and again I want to reassure the people of Te Atatu that we are doing everything we can to identify and apprehend the person responsible," he says.
Police still urge nearby residents to examine their own properties in detail and check doors and window frames for scratches, check for soil on door frames or outside, which could have come from shoes, and check for footprints or dirty marks on outside window ledges.
Police are asking residents to leave anything found to be out of place as it was and to call them.
Police have set up a number – 0800 772 271 – for people to provide information to the Operation Nepal homicide investigation team, or residents can alternatively call Crimestoppers anonymously on 0800 555 111.
Police say it is too early to speculate on the cause of Ms Tian's death. One possibility they are investigating is whether the attack was the result of a burglary gone wrong, but they are "keeping an open mind as the investigation has gone forward".
Police are expected to be at the scene for at least another week.
A vigil will be held for Ms Tian tomorrow at 7pm at the Te Atatu Baptist Church.
3 News
