Detectives hunting the killer of a 22-year-old care worker appealed for help from pub-goers and business owners today.
Ffion Wyn Roberts was found strangled in a stretch of water close to her home in Porthmadog, North Wales.
Police believe CCTV or mobile phone pictures taken around the time she was murdered could hold clues to the killer's identity.
Ffion, who was planning a career as a nurse in the Army, had spent Friday night at the Union public house in the neighbouring village of Tremadog but left to walk home, alone, at around 3.30am Saturday morning.
That was the last time Ms Roberts was seen alive. Her body was found in a canal drain later that day.
North Wales Police today asked for pub-goers who may have taken photographs while they were out on Friday night to pass the images to detectives.
Officers say a number of people who were at the three local pubs - the Union, the Fleece and the Madoc - have already come forward with information and photographs taken on mobile phones, but they believe that there may be more pictures available.
Business owners and residents who have CCTV are also being asked to hand over their images.
Detective Superintendent Peter Chalinor, the senior investigating officer, said: "The support from local people has been tremendous and we are very grateful to everyone who has come forward so far.
"There may, however, be other people who were out on Friday night who may have taken photographs and we would like to hear from them.
"There may just be something that they can tell us or we can see from an image that might help the investigation."
Ffion, who was single, is believed to have started off her journey home on foot along Church Street to Porthmadog.
More than 100 officers are now working on the murder investigation. Forensic examinations of the area where she was found, a drainage channel known as Y Cyt (The Cut) close to a disused canal, continued today along with house-to-house inquiries.
Mr Chalinor added: "We will continue to invest a large amount of resources into the investigation, but local people also have to act responsibly.
"There is nothing at the moment to suggest that this incident is related to any other alleged incidents, neither is there anything to suggest that this was anything other than a one-off attack.
"Nevertheless, it is prudent for us to advise local people to be vigilant and not to walk alone late at night or during the early hours of the morning."
Mr Chalinor also said police family liaison officers are also continuing to support Ffion's parents, Idris and Bethan, her younger brother Elgan and their extended family.
In a tribute, the family described Miss Roberts as "thoughtful and caring".
Anyone who was in Tremadog or Porthmadog between 3.30am and 8am on Saturday April 10 is asked to contact the incident room on 01745 538474, or by dialling 101 from anywhere in Wales, or Crimestoppers on 0800 555 111.Reuse content