Lawyer Harvey Silverglate, who overlapped with Robert Mueller at Princeton University and who dealt with him personally on at least a couple of cases, has what I thought was a pretty interesting column running at the WGBH website under the headline "How Robert Mueller Tried To Entrap Me":
I have known Mueller during key moments of his career as a federal prosecutor. My experience has taught me to approach whatever he does in the Trump investigation with a requisite degree of skepticism or, at the very least, extreme caution.