1. That the employee engaged in statutorily protected conduct, i.e., either participation or opposition;
2. That the employee suffered adverse treatment; and
3. That a causal connection exists between the protected conduct and the adverse treatment. This nexus normally is established for purposes of a
prima facie case by proof that the protected conduct preceded the adverse treatment and proof of the employer’s knowledge of the employee’s protected activity prior to taking the adverse
action.
American Bar Association // Section of Labor and Employment Law
Equal Employment Opportunity Committee // EEO Law Basics // Spring 2006