The loose cannon crossed the line that the employer can no longer afford. Create a policy that forbids all forms of harassment and destructive interpersonal conduct regardless of the legally protected status of victims. Make a stand against psychological violence. Extend civil rights protections and safety assurances. Develop an enforcement mechanism that promises to be free from interference from senior management.
Progressive discipline is warranted for violators.
But guilty violators must be punished. If the complaint system turns into politics and favoritism as usual, the policy is rendered useless. Reverse the upside down world of rewarding aggressors and expelling the more competent targets. Relate humane treatment of employees to the organization's Values and Mission. Re-educate managers that destructive misconduct is not a component of acceptable management practice.