Shouldn't there be prosecutions?

Yesterday we learned that the Department of Corrections had agreed to compensate 15 women for illegal internal searches carried out at Auckland Region Women's Corrections Facility between 2006 and 2016. Corrections had been "suspecting" people of internally concealing contraband (none was ever found), locking them in solitary confinement in a "dry room" to allow material to pass, then proposing they "consent" to an internal search - clearly outlawed by the Corrections Act - in order to be released. There can be no consent of any kind in a prison, and the prisoners are being compensated for torture and degrading treatment, which is appropriate. But as the article points out, the searches "constitute[d] the offence of sexual violation under the Crimes Act". So shouldn't the staff who arranged and conducted them be prosecuted for that offence? Or are we happy for guards to sexually violate prisoners in our prisons?