On the 15th of November 1983, Eila Karjalainen (23) was found deceased off a layby at Barnham Woods, Woodstock Oxfordshire. Eila was a Finnish nurse who was thought to be hitchhiking in the UK to sightsee. She was staying at Shaw’s Field Farm, Chinnor Hill.
Her rucksack and belongings including her passport were found in a layby on the A40 near Barnard Gate, near Witney, three weeks after her remains were found. Aila was known to write down the names of people she met in a diary. When this was found several pages were ripped out. Fingerprints were subsequently taken from the backpack and other items such as tickets but have yet to be matched to anyone in the system. Eila's cause of death was ruled as strangulation.
There is a theory that Eila may have been a victim of serial killer Christopher Halliwell who worked as a taxi driver. However, Halliwell would only have been 18 and his only confirmed crimes took place in the 2000s. However, it's important to note that he is expected to have committed many more murders than he's been convicted for.
Sources
https://www.oxfordmail.co.uk/news/6627435.1983-murder-new-evidence/
https://www.bicesteradvertiser.net/news/11450344.working-bring-killers-justice-last/
https://reasonedcrimechronicle.com/not-to-be-forgotten-eila-karjalainen-unsolved-murder-1983/
http://www.caledoniankitty.co.uk/2022/01/christopher-halliwell-how-many-do-you.html