This is the 140th most frequent Indonesian word.
resmi
Official.
The word 'resmi' here is used as an adjective to describe the nature of the event as official or formal.
Upacara ini adalah acara resmi yang dihadiri oleh banyak pejabat.
This ceremony is an official event attended by many officials.
In this sentence, 'resmi' is used as an adverb, indicating that the action of announcing was done in an official manner.
Pengumuman tersebut sudah resmi diumumkan oleh pemerintah.
The announcement has been officially declared by the government.
Here, 'resmi' qualifies 'evidence', meaning the evidence is recognized and formalized as official by the court.