The 32-year-old was discovered dead on Paekakariki Hill Road, north of Wellington, next to his damaged car on Friday morning, after sustaining fatal stab wounds.
Police have cordoned off an Oxford Terrace house in Lower Hutt as part of their investigation into his death.
Detective Senior Sergeant Mike Sears said it was too early to say if Mr Stevens had been at the property.
"But we believe it was [his] intention to visit the property after he left his home address at around 10pm on Thursday night.
"Today we are releasing CCTV images of Mr Stevens at Countdown on High Street in Lower Hutt where he has purchased some alcohol at around 10.30pm."
We are hoping these images will help jog people's memories and that they'll be able to assist us with where Mr Stevens went after this."
"We are in the process of reviewing the forensic results of his vehicle and at this stage don't believe that he was killed inside his vehicle."
Police said anyone who had seen Mr Stevens or his white Toyota Corolla, registration RZ1852, after 10pm on Thursday should call 04 381 2000 and ask Mr Stevens' family last saw him on Thursday about 10pm, Mr Sears said.
Police were yet to establish when the assault happened.
Mr Sears said anyone with information should call 04 381 2000 and ask for the Operation Vintage investigation team, or provide information anonymously through Crimestoppers on 0800 555 111.
NZME.