This is the 11594th most frequent Turkish word.
faili
"Faili" in Turkish means "perpetrator" or "doer."
Here, 'faili' is used in the form 'faili meçhul', which means 'unknown perpetrator'. It modifies 'cinayet' (murder) to indicate that the individual who committed the crime is not known.
Faili meçhul bir cinayet üzerinde çalışıyorlar.
They are working on an unsolved murder case.
In this sentence, 'failini' is the accusative form of 'fail', meaning 'perpetrator'. It is used to refer to the person who committed the crime in context.
Polis, suçun failini bulmaya çalışıyor.
The police are trying to find the perpetrator of the crime.
Here, 'faili' is used in the nominative form as a part of the phrase 'faili olduğu iddia edilen kişi'. It refers to someone accused of being the perpetrator.