Officers spent the day searching Walter Day Park in Dayton, which is just minutes from Ms Dweh's body was found, after recently uncovered information lead them to believe the suspect passed through the park twice on the night of the murder.
Detectives have spent the afternoon scouring the parkland with particular focus on a set of bushes.
So far, nothing pointing to the killer has been collected from the Park.
Police believe the mother of three was murdered in her home on October 3, with the killer or killers spotted at the park at around 7pm.
"We've received some information from the public recent information that led us there this afternoon," Detective Superintendent Rod Wilde said.
"Members of the police homicide squad, forensic division and a police Airwing drone are here."
While no promising leads have so far come from the park, police are confident they'll catch the killer.
"We believe there has been a degree of premeditation in relation to this offence and certainly a degree of planning," Det. Supt Wilde said.
"Certainly, the investigation is progressing and I'm confident that will resolve it and we'll charge the person or persons responsible for Janet's murder."
Eight months pregnant, the 36-year-old was just weeks away from giving birth to her fourth child.
Her body was discovered by her brother at her home on Mataro Drive, near Garrido Way, in Dayton at around 6pm on Monday October 4.
Police are appealing for anyone who was in the area on the evening of October 3 or may have dashcam vision to contact Crime Stoppers.