Alfred Woodley, who is now 85, discovered the 17-year-old's clothes and headband dumped in a barn in Beenham on Sunday, October 30 1966.
Her naked body was recovered from a waterfilled ditch later that day.
Speaking to the Chronicle on Tuesday - 24-hours after David Burgess was jailed for life for Yolande's murder - a weary Mr Woodley dropped his grass trimmer in the graveyard of St Mary's Church, where his late wife is buried, and stopped his maintenance work to reflect on the horrific events.
He said: "There were coppers everywhere. Everyone knew why.
"On Sunday afternoon I went into the barn with my father-in-law to get hay for the cattle and we found all the clothes.
"It was a huge shock, I couldn't believe it - it's not what you'd ever have expected in Beenham."
Burgess, who had a glass eye, was 19 at the time and a strong suspect, but was not arrested until six months later - and that was for murdering Beenham nine-year-olds Jeanette Wigmore and Jacqueline Williams.
The 65-year-old is serving a double life sentence for their murders and was arrested again last year when Yolande's death was re-investigated.
On Monday at Reading Crown Court he was ordered to serve at least 27 years for Yolande's murder.
Mr Woodley said: "I didn't have much to do with Burgess but I could see it in his eyes, you could tell something wasn't right with him.
"It's a big relief that he's been brought to justice."
Yolande left her Newbury home to work as an au pair for a Beenham farmer's family just five days before her death, but the village still carries the scars and has remained the focus of media attention - despite residents' best efforts to move on.
This week was no different and as the sun beamed down on The Six Bells pub - where Yolande was last seen alive - Beenham's lanes and footpaths were largely deserted.
Dog walkers hurried on, refusing to comment on the village's bloody history, others simply slammed their doors.
One woman who has lived there for 20-years said: "It has been a stain on the village.
\"Beenham has almost become synonymous with those tragic deaths but residents want to respect the memories of the victims and to be able to move forward.
"Hopefully now we can."