1)
What is the law after he is brought to trial?
1.
Rashi: If he is exempted from exile, he is exempted. If he is obligated, he is returned to his Ir Miklat. Radak
2)
Why is he exiled until the Kohen Gadol dies?
1.
Refer to Bamidbar 35:25:2:1-4 and the notes there.
