Police have issued a new appeal for information about an armed robbery at the Gulf petrol station in Denny in central Scotland.
Officers first released a description of a man thought to have escaped with a three-figure sum of cash, but now say it is possible the robber could have been female.
The filling station on Glasgow Road was targeted at 21:40 on Tuesday.
Investigating officers are also looking for a teenage girl seen nearby who may have been a witness.
Police said the "male or female" suspect made off in the direction of Paris Avenue, having demanded cash from the attendant who was closing up the station.
He or she was white, aged 16 to 30, between 5ft 8in and 6ft tall, of slim build and wearing dark clothing including a black hoodie.
The potential witness, who police said may have “key information”, was seen walking on Glasgow Road in the direction of the petrol station five minutes before the raid.
She was described as being 13 to 16 years old, 5ft 3in tall with dark hair worn in a donut bun. She was wearing a dark long-sleeved jumper and skinny jeans.
A Police Scotland helicopter helped with the initial search, and detective inspector Graeme Hendry said there was a “dedicated team in place” investigating the crime.
He said: “I appeal to householders in the area, particularly around Paris Avenue, to come forward if they believe they heard or saw anything suspicious.
“We would also ask them to contact us if they have CCTV in their home which would be valuable to us.”