Mimic what the big firms are doing - look to the consulting firms like Deloitte or PwC or Accenture and analyze their hiring process. Do as much as possible to prevent bias prior to the in-person interview and make the in-person interview as quantitatively scored as possible. Sometimes bringing in outside counsel for this specific problem, or hiring a recruiting agency can help solve these issues. The first step to counteracting bias, however, is being aware of it and prioritizing the mitigation of it.