‘Can I sue my attorney for not revealing the fact that there was an easement across my property at closing? We tried to resolve this matter amicably. He admitted (in writing) that he knew about the easement but CHOSE not to inform us not to include it in the Deed.’
The answer to the question “Can I sue person X?” is always yes. The real question is can you sue him and win, and that depends on the facts of the case.
If you actually have written evidence that the attorney purposely withheld material information, you probably have a pretty good case. I suggest you find another attorney who you can trust to explore it further.