The mother-of-four aged 37 was found dead on State Highway 1 about 10km from Bluff, after a motorist ran her over at about 12.50am on Monday.
Detective Sergeant Mark McCloy said several detectives were investigating the death of Ms Schmidt and investigators were awaiting the results of forensic examinations.
Police had spoken to between 10 and 12 witnesses and were not actively seeking any more information from the public.
"We are pretty happy we know her movements," Det Sgt McCloy said.
"Several witnesses saw her walking alone on the highway on Sunday night."
Ms Schmidt was holidaying in New Zealand with her Australian partner.
It is understood the pair spent three or four days in New Zealand before Ms Schmidt's death.
The pair spent time in Queenstown before travelling to Southland.
Ms Schmidt's body was discovered on State Highway 1 after being hit by a Bluff motorist.
Earlier this week, police said they believed she might have been killed before she was struck by the car.
However, yesterday they would neither confirm the cause of death nor discuss the findings of a postmortem examination by ESR.
Det Sgt McCloy said he wanted to thank the public for their assistance in the investigation of Ms Schmidt's death.