Top criminologist Xanthe Mallett speaks about missing teen Pheobe Bishop, 17, after multiple bombshell twists

Police have now declared multiple crime scenes in the case of missing teen Pheobe Bishop, 17, with a top criminologist saying it was an “unusual” and “concerning” development for the investigation.

Investigators have declared a crime scene at a property in the rural town of Gin Gin, 50km west of Bundaberg, Queensland, where Bishop lived with two people who were not direct family members.

Police have also seized a grey Hyundai ix35 which Bishop was last seen travelling in to Bundaberg Regional Airport and which belonged to one of the teenager’s housemates.

Police are now working on the theory Bishop never made it to the airport last Thursday.

She was due to board a flight to Western Australia on May 15 but she never checked in.

Criminologist Xanthe Mallett said police appeared very concerned for the teen’s welfare, as she discussed the latest developments with Sunrise host Nat Barr on Thursday.

“Certainly, they are concerning developments,” Mallett said.

“It is unusual for the police to declare a crime scene at a (missing) person’s home. They would obviously go there and search for clues as to where they may be ... but they are very concerned for Phoebe’s welfare at this stage.”

Barr pressed Mallett on reports the teenager was seen arguing with the driver of the Hyundai.

Mallett said: “That’s very significant, because that may well be the last known sighting of Pheobe before she vanished.

“They will certainly be trying to plot the time between when the car left the property and when she vanished.

“They will be looking for witnesses that can corroborate anybody’s movements, especially those people who may have been the last to see her or (the) last known to have seen her.

“(They will be) talking to as many people as possible, trying to figure out in the days and weeks and hours leading up to Pheobe’s disappearance, who was with her.”

Bishop’s bank account has also not been accessed since she was reported missing.

Bishop’s mother has been pleading for help on social media to find her missing daughter.

“This is really worrying for the family and my heart goes out to them,” Mallett said.

“I’ve seen some of the social media posts and I really wish the police could provide better news a week on.

“But this is very suspicious.

“This is not a young woman who would normally disappear without speaking to her family. I’m very concerned for her as are the police.”

Pheobe is described as approximately 180cm tall, with a pale complexion, long dyed red hair, and hazel eyes.

She was last seen carrying luggage and wearing a green tank top and grey sweatpants.