This issue first came to my attention in a meaningful way well before I began the practice of law, back when I was Kinko's manager. The majority of problems in my store's workforce were caused by one or two individuals who had unstable temperament, a skewed view of their role in both the business and life, and, critically, a persistent willingness to cross boundaries inappropriately.
Not coincidentally, in the practice of law an overwhelming percentage of the problem cases are where either my client or the opposing party or counsel demonstrates the same traits.
Ever since I first came to understand the problem I have looked for an organized way to approach analyzing people to detect or rate the likelihood of such problems up front. Unfortunately, prospective employees, prospective clients, and for somewhat inexplicable reasons, opposing counsel, all seem to bristle when requested to report to a psychologist for a full battery of testing. Additionally, at least with regard to prospective employees, in the vast majority of hiring situations such a request would likely be a violation of numerous statutes, including the ADA.
One option that is useful in many situations is the evaluation process set forth by David J. Lieberman, Ph.D. in his book "Find Out Who's Normal and Who's Not." I found it on the sale table and decided to give it a read about a year ago. It contains a snapshot quick test, a detailed evaluation you can apply when you know more about an individual, and a list of separate, specific red flag items.
I have applied the system Dr. Lieberman puts forward and have found it to be useful, although not infallible.
While, I do recommend his book and system, what I recommend even more strongly is that each reader find a system with which they are comfortable that is more advanced than the gut feeling, "I like my new boss" or "This new employee sure seems like a nice lady." It is easy to mis-assess the reality of the situation given the excitement and desire to proceed with a new job relationship and fail to recognize the personality problems in the offing.