A con man has been using a large number of aliases to get money from wealthy, single women. Some he has affairs with, some he probably just defrauds. He has a wife and son but he is such a narcissist that the only person who matters is himself.
When the conman turns killer and a police officer thinks he knows exactly who he is dealing with, the BAU investigate. Pity they didn't actually do any proper profiling. Also, a pity we saw more of the unsub, his victims and his family than we did of the regular cast.
More than a little yawn worthy in my opinion but, then again, there have been plenty of those in Season 5.