A fresh twist has emerged in the disappearance of a data scientist who vanished seven months ago as one of her Facebook accounts under the name ‘Red Riding Hood’ is mysteriously deleted.
Kathleen Riethmuller walked into Elephant Backpackers, in the inner Sydney suburb of Woolloomooloo, on October 28 in a ‘jittery’ state to make a booking to stay the night – which she would never fulfil.
She abruptly left reception without first visiting her room before heading to Sydney’s north, where she was last seen on security footage visiting shops before walking along a busy road.
Hours later, the 28-year-old’s belongings including her ID and bank cards were found abandoned 7km away in a backpack in a street at Lane Cove, while her phone was discovered by another member of the public in a neighbouring suburb.
A nationwide appeal to find her has proved fruitless and police hold serious concerns for her welfare as distraught family have not heard from her since.
Kathleen Riethmuller, 28, (pictured right) has been missing for seven months since she mysteriously vanished from Sydney’s northern suburbs
Now, Daily Mail Australia can reveal one of Ms Riethmuller’s social media profiles has been deactivated sometime since November, and she is known by police to use a series of aliases.
The development comes after the former statistics analyst was recently added to the Australian Federal Police’s missing person’s register – reserved for the handful of cases where people have not been located for three months or more.
While police had initially reported her phone was found in the backpack, the AFP website states it was discovered separately in Lane Cove North.
In another baffling turn, the database information also revealed the young professional is known to use the aliases Amy Munroe, Kate Riethmuller, Margaret Riethmuller and Kate Muller.
According to social media profiles, Ms Riethmuller graduated from Brisbane Girls Grammar – which costs about $26,555-a-year – in 2010 before studying a Bachelor of Business Management/ Science at The University of Queensland.
In one of her Instagram accounts, Ms Riethmuller said she worked in ‘data science, innovation and market developments’ with ‘experience in consulting, finance and start-ups’.
One of Ms Riethmuller’s Facebook profiles, under the name ‘Red Riding Hood’ has been deleted since November. She is pictured in a post from May 2021 – which was on the now-deactivated account
Police inquiries revealed Kathleen attended a retail store on Reserve Road, Artarmon, about 11.40am on Thursday 28 October (pictured, left), before she was spotted again at 2.30pm the same day in North Sydney, wearing a long sleeve denim dress and black flat shoes (right)
She frequently posted photos of work conferences and new technology projects she was taking part in between 2017 to 2019, when the account appears to have become inactive.
A newly uncovered profile of Ms Riethmuller’s on Goodreads has painted a picture of the books and topics that interested her in the months leading up to her disappearance.
Frequently occurring genres among her dozens of reading lists include entrepreneurship and finance, self-help, mental health, career and business, and fiction classics.
In July 2021, she added the titles ‘The Million Dollar Mindset: How to Harness Your Internal Force to Live the Lifestyle You Deserve’, ‘How To BEcome A Successful Artist’, and ‘Breaking the Habit of Being Yourself: How to Lose Your Mind and Create a New One.’
Although the account does not appear to have had any activity since that time, one reading list containing five books – mainly poem collections and classics like Memoirs of a Geisha – is named ‘Kat’s-fiction 2022’.
A family friend previously told Daily Mail Australia a ‘jittery’ Ms Riethmuller checked into Elephant Backpacker (pictured) in, Woolloomooloo, the morning she disappeared
She was last seen on CCTV walking eastbound on Falcon Street (pictured), North Sydney, towards Neutral Bay
A member of the public later found her belongings, including her ID and bank cards, in a backpack 7km away on Centennial Avenue (pictured) at Lane Cove
A map posted in a Facebook page dedicated to finding Ms Riethmuller shows her known movements around Sydney around the time she disappeared. The AFP has since updated her last sighting, which was on Falcon Street near Neutral Bay
In the weeks before her disappearance, Ms Riethmuller tried to sell a string of possessions on Gumtree , with police previously revealing they were exploring the possibility she travelled to Melbourne for work opportunities.
In 2021, more than 53,000 missing persons reports were made to Australian police, with over 98 per cent found – most of whom were safe and well.
After checking into the backpacker hostel, Ms Riethmuller attended a Bunnings store on Reserve Road, Artarmon, about 11.40am on Thursday 28 October.
She was spotted again at 2.30pm the same day in North Sydney, wearing a long sleeve denim dress and black flat shoes.
She was last captured on CCTV 15 minutes later walking eastbound on the northside of Falcon St towards Neutral Bay.
Her backpack was found by a member of the public later that afternoon on Centennial Avenue, Lane Cove, sparking the investigation into her whereabouts.
NSW Police first issued a public appeal for help finding Ms Riethmuller on October 31, which was renewed two weeks later as leads ran cold.
While she was in regular contact with her family, Ms Riethmuller was very private – offering them very few details about her friendship circles or life in Sydney since she moved to the city about five years ago.
Police hold serious concerns for Ms Riethmuller (pictured), who has not been in contact with family since October
The data scientist’s public profiles reveal the books of interest she downloaded in the months before she vanished
Ms Riethmuller said she worked in ‘data science, innovation and market developments’ with ‘experience in consulting, finance and start-ups’ on her online profiles
A family friend, who wished to remain anonymous, previously told Daily Mail Australia Ms Riethmuller’s Brisbane-based family were distraught by her unusual disappearance.
‘Her family are very devastated and a bit at ends because there are not any leads to go off at the moment,’ the friend said.
‘A lot of information has come through to police but there have been no verified sightings of Kathleen since the day she went missing.
‘The situation is bewildering. Her family is very confused and really just want to get her back.’
Ms Riethmuller is described as Caucasian, about 165cm – 175cm tall, with a thin build and long dark hair.
Anyone who may have information about her whereabouts or has seen her is urged to contact Chatswood Police Station or Crime Stoppers on 1800 333 000.
In the week leading up to her disappearance, the 28-year-old listed several items for sale on Gumtree (pictured, left and right)