"An Irish bishop has resigned, weeks after his handling of child sex abuse allegations was severely criticised.
A report on abuse by priests in the Dublin Archdiocese found Donal Murray's handling of one case while an auxiliary bishop in the 1980s was "inexcusable".
The Vatican said the Pope had accepted his resignation as bishop of Limerick. ....."
http://news.bbc.co.uk/2/hi/europe/8417507.stm
If he knowingly protected criminals and, in other words, perverted the course of justice then he surely has to be prosecuted too.
In this case "pervert" is very apt.