Samantha Murphy was last seen leaving her home on Eureka Street in Ballarat East to go for a run about 7am on Sunday,February 4.
Patton said Murphy and her family did not know Stephenson.
This masthead has reported Stephenson was partying with friends in central Ballarat the night before Murphy disappeared.
A witness who had been approached by police,but asked not to be identified to protect his business,said investigators had visited Ballarat venues to collect footage of Stephenson on that Saturday night.
A social media post purporting to show Stephenson snorting a white substance off a mobile phone screen with friends has also circulated among the local community.
Police have seized a four-wheel-drive parked outside the property where Stephenson was arrested.