Helping nursing staff cope with drug diversion investigation

Recently I was part of a leadership/management group that reviewed evdience that I had found that one of our employee's was misusing controlled drugs. An investigation found a second agency person was involved as well. A further investigation studied the controlled drugs use in our ER for the last several months and that one found no addional misuses. Another words the rest of our staff are in the clear. Very little has been said due to legal reason which only causes the rumor mill to increase it's output. Many of the nurses are nervous, some feel betrayed.
I would like to ask for peoples opinons and suggestions for helping the staff deal with this.