Spanish to English Law/Patents Law (general) appeal

The document is a judgement appeal, recurso de casacion, made to the supreme court by three individuals convicted of crimes against public health. They allege various infringements of human rights and as such their appeals have been considered and were eventually rejected.

Below is the context in which the above term appears:

Labor que, en todo caso, ha de partir de un principio esencial, cual es el de la intangibilidad de la
narración de Hechos llevada a cabo por el Tribunal de instancia, sobre la convicción que por el mismo se alcanza acerca de la realidad de lo acontecido, como consecuencia de la valoración del material probatorio disponible, que le es propia.

I understand the general context, The court has reached a conviction based on various information here, one being the information disclosed perhaps in proceedings.

This is where I am stuck 'reality of proceedings' is far too literal and makes no sense, perhaps 'development in proceedings'

Thank you all