What does Joshua 20:6 mean?

The accused has to stay in that city until they’ve stood trial in front of the community and until the high priest who’s alive at that time dies. After that, they can go back home, to their own town. Joshua 20:6 - Modern Text Bible

(The person who caused the death gets a fair trial and protection until the high priest dies, which marks a kind of reset. Then they’re free to return home, showing both justice and mercy.)