@TomSea Ms. Smith is not listed as an attorney with the firm, so I gather she is a secretary, paralegal or some other member of the firm's support staff. As such, Mr. Langer would be her boss. In the firms I worked for as a secretary, I had two attorneys as my immediate supervisors, but really, I worked for all the attorneys, particularly the partners. Support staff worked for the whole firm.
I suppose as managing partner, Mr. Langer had overall responsibility for hiring and firing of attorneys in the firm. But depending on the partnership setup, he may have needed approval of the rest of the partners in order to drive out one of the partners. That might have been why Mendoza also shot the other partner, Mr. Beck. I don't know what was going on in Mendoza's mind, but he seemed to have more than one specific target in mind -- not just Mr. Langer.
But like I said, we're doing some armchair sleuthing (more like "guessing" here). I really don't want to argue.